Tag: Astronomy

Anyone with a reasonable interest in astronomy will recognise the above image as containing the Drake Equation, sometimes referred to as “the second most famous equation after E=Mc2

It was first proposed in 1961 by American astronomer and astronomer and astrophysicist Dr. Frank Drake as a probabilistic argument to estimate the number of active, communicative extraterrestrial civilisations in the Milky Way Galaxy. Its values are defined as:

N = the number of civilisations in our galaxy with which communication might be possible (i.e. which are on our current past light cone);

And:

R_∗ = the average rate of star formation in our Galaxy.

f_p = the fraction of those stars that have planets.

n_e = the average number of planets that can potentially support life per star that has planets.

f_l = the fraction of planets that could support life that actually develop life at some point.

f_i = the fraction of planets with life that actually go on to develop intelligent life (civilisations).

f_c = the fraction of civilisations that develop a technology that releases detectable signs of their existence into space.

L = the length of time for which such civilizations release detectable signals into space.

In the decades since its initial publication, the Drake Equation has been widely critiqued by astronomers and mathematicians because the estimated values for several of its factors are highly conjectural  such being that the uncertainty associated with any of them so large, the equation cannot be used to draw firm conclusions.

However, these critiques actually miss the point behind Drake formulating the equation in the first place, because he was not attempting to quantify the number of extra-solar civilisations which might exist, but rather as a way to stimulate scientific dialogue about what had been very much looked upon as an outlier of research, and to help formulate constructive discussion on what is regarded on the first formalised discussion on the search for extra-terrestrial intelligence (SETI), as he noted in his memoirs:

As I planned the meeting, I realised a few day[s] ahead of time we needed an agenda. And so I wrote down all the things you needed to know to predict how hard it’s going to be to detect extra-terrestrial life. And looking at them it became pretty evident that if you multiplied all these together, you got a number, N, which is the number of detectable civilizations in our galaxy. This was aimed at the radio search, and not to search for primordial or primitive life forms.

– Frank Drake

Frank Drake not only hosted the first US meeting to discuss the potential for seeking signs of possible extra-terrestrial civilisations, he pioneered several of the earliest attempts to seek any such signals as demonstrating methods that might be used as a means to intentionally communicate our existence to other civilisations within the galaxy. As such, his work did much to put our speculative thinking about intelligences elsewhere in the galaxy on a solid foundation of scientific research, as will as being responsible for some for the foremost research in the field of modern radio astronomy.

This is his story.

Born in Chicago on May 28th, 1930, Frank Drake was drawn to the sciences and to electronics from an early age, and in order to further his education in both, he enlisted in the US Navy Reserve Officer Training Corps (ROTC).  This allowed him to obtain a scholarship at the prestigious Cornell University, ostensibly to obtain qualifications in electronics, but also study astronomy.

While at Cornell, Drake’s astronomy class were able to attend a lecture by astrophysicist Otto Struve. While his name may not be instantly recognised, Struve was one of the most distinguished astronomers of the mid-20th century, a member of a generational family of astronomers stretching by to the 18th century and Friedrich Georg Wilhelm von Struve. He was also one of the first astronomers to openly promote radio astronomy as a key to determining whether there might be other intelligences living in our galaxy – an idea his contemporaries tolerated, rather than embraced.

Struve’s presentation positively affected Drake, and following his required 1-year military service following graduation in 1951 (served as the Electronics Officer aboard the cruiser USS Albany), Drake enrolled at Harvard University, where gained his doctorate in astronomy, with a focus on radio astronomy.

In 1956 Otto Struve was appointed as the first director of the National Radio Astronomy Observatory (NRAO)), and he started overseeing the establishment of a number of national radio astronomy centres across the United States. One of these was at Green Bank, Virginia, a facility Drake joined as a researcher in 1958. His initial work here started with the static arrays at Green Bank, carrying out the first ever mapping of the centre of the Milky Way galaxy, and the discovering that Jupiter has both an ionosphere and magnetosphere.

However, Struve was keen to enhance the facilities with steerable radio dishes, and to this end purchased an “off-the-shelf” 26 m dish and had engineer Edward Tatel (for whom it was later named) design a motorised mount for it so it could be pointed around the sky. This work was completed in 1959, and Struve turned to Drake to formulate the telescope’s first science mission.

At the time, Drake had just read an intriguing article in Nature magazine entitled Searching for Interstellar Communications. Within it, physicists Giuseppe Cocconi and Philip Morrison proposed using a large radio dish to monitor “incoming” radiation from stars along the 21-cm / 1,420.4 MHz wavelength – the radio frequency used by neutral hydrogen.  Given this is the most common element in the universe, Cocconi and Morrison speculated it would be logical landmark in the radio spectrum to manipulate as a message carrier.

Taking this idea, Drake developed Project Ozma, a three-month programme run at the start of 1960 to listen for any signals coming from the vicinity of either Tau Ceti or Epsilon Eridani. At the time, no-one knew if either star fielded planets (although both were found have at least one planet orbiting them almost 50 years after Drake’s experiment).

Following Ozma, Drake was encouraged to formalise SETI research into a more co-ordinated effort (various programmes, such as Ohio State University’s work using the Big Ear telescope, were already in existence but without any real coordination). To this end, he helped put together the first small-scale meeting / conference on the subject in 1961 – the event at which he used his equation to  stimulate the discussion.

Among those attending were Otto Struve (now retired), Phillip Morrison, astronomers Carl Sagan and Su-Shu Huang, chemist Melvin Calvin, neuroscientist John C. Lilly, and inventor Barney Oliver. Together they called themselves The Order of the Dolphin (due to  Lilly’s work on dolphin communications), and together they laid the groundwork for a systematic approach to SETI research, which over the coming years would in turn give birth to numerous programmes, and more fully legitimise such research within scientific circles.

In the mid-1960s, and still based at Green Bank, Drake was nominated to spearhead converting the massive Arecibo Ionosphere Observatory  – originally built as a project to study the Earth’s ionosphere as a means of detecting nuclear warheads inbound towards the United States – into what would become more famously known as the Arecibo Observatory, for several decades the largest radio telescope in the world.

This work finished in 1969 when the National Science Foundation formally took over the Arecibo faculties, and two years later Drake was approached by Carl Sagan with another intriguing proposal. Sagan had himself been approached English journalist Eric Burgess – who at the time was writing about the upcoming NASA Pioneer 10 and Pioneer 11  missions – about the idea of sending a physical message out to the stars.

Continue reading “Space Sunday: equations and launch scrubs” →

The above image may not look to be much, but it in fact a glimpse at one of the most distance galaxies from our own, a place called Gz-13. It is so far away, the light captured by the image departed it about 300 million years after the universe itself was born.

Gz-13 is a part of a cluster of galaxies seen within one of the first set of images released by NASA from the James Webb Space Telescope (JWST), and which I covered in my previous Space Sunday update. So far away are these objects, that they can only be seen via the effect of gravitational lensing – using the gravity of an object much, much closer to our own solar system to “bend” the light from them and focus it so that JWST can capture images.

Gz-13 lies tucked away in the SMAC-0723 grouping of very distant objects. Originally imaged by the Hubble Space Telescope (HST), the grouping has been given sharp, new high-definition exposure by JWST. Some much definition, in fact, that GZ-13 hadn’t been seen by Hubble.

While it may seem like a blob of red-shifted light, massively distant objects like Gz-13 (and Gz-11, another far-distant galaxy that was seen when Hubble viewed SMACS-0723) are important targets for study, as they represent a period of time literally just a blink (in cosmic terms) after the universe went off with its Big Bang; thus thus represent an opportunity for us to understand what was going on very close to the origin of literally everything there has ever been.

What is particularly interesting about the likes of Gz-11 and Gz-13 is that despite being formed just 150-200 million years after the first stars are believed to have started forming, they still have masses that suggest they are home to several billions stars with a mass equivalent to our own Sun. Thanks to them being so bright in the infra-red, they offer an unparalleled opportunity for astronomers to carry out extensive spectrographic analysis  to help us to discover more about them and the nature of the stars they contain – including, potentially, whether any of their stars might be surrounded by disks of dust and gas that might have gone on to form planets.

Given the nature of the expanding universe, Gz-11 and Gz-13 are liable to be just the tip of a massive iceberg of galaxies far, far, away that are waiting for JWST to find. This is turn will massively increase our total understanding of the nature of the universe, and the formation and growth of the galaxies within it. In fact, it is very possible that JWST will look so far out that we are looking almost back to the very edge of the Big Bang itself.

China Launches First Space Station Science Module

China has launched the first of two science modules to its nascent Tiangong Station (TSS).

The Wentian module was lifted into the sky atop a Long March 5B heavy-lift rocket at 06:25 UTC on Sunday, July 24th, the launch taking place from the Wenchang spaceport on the southern island of Hainan.

Measuring 17.9 metres in length and with a diameter of 4.2 metres, the module has an operational mass of around 23 tonnes, putting it on a par with US and international modules on the ISS. At the time of writing, the module was due to make an automated docking manoeuvres with Tianhe-1, the core module of the Chinese space station.

Wentian, which literally means “quest for the heavens,” is the first of two science modules intended to join with Tinahe-1 to complete the currently-planned elements of TSS and bring its all-up mass to around 66 tonnes (the ISS, by comparison, masses 460 tonnes). In addition, operations aboard the station can be added-to through the use of Tianzhou automated re-supply vehicles.

The module’s docking will be overseen by the three crew of the Shenzhou 14 mission. It will initially dock with Tianhe’s forward docking port, where it will remain during initial tests and check-out by the crew to confirm its overall condition. The crew will then commence initial science activities, which will include a live broadcast via Chinese state media.

At some point in the future, Wentian will be relocated to a side port on Tianhe’s forward docking hub to form one arm of an eventual “T” that will be made by the core module and the two science modules, leaving the forward port free for visiting crews, and the after port at the far end of Tianhe available for visiting Tianzhou vehicles.

Whilst classified a science module, Wentian is actually a multi-purpose facility. It includes an airlock of its own to enable crew members to complete space walks, it has an external robot arm of its own to assist with such spacewalks, and additional living space for 3 tiakonauts, allowing up to six to live in comfort on the station during hand-over periods. The first such hand-over (similar in nature to ISS handovers) is due to take place in December 2022, when the crew of Shenzhou 14 pass the station over to the 3-person Shenzhou 15 crew. However, prior to that event, the second science module, called Mengtian (“Dreaming of Heavens”), is due to be launched to the station in October.

NASA Sets Artemis-1 Launch Dates

On July 20th, 2022, NASA announced they are targeting three dates at the end of August / beginning of September for the first flight of their Space Launch System (SLS) super rocket which sits at the heart of their plans for a return to the Moon.

The Artmis-1 mission will launch an uncrewed Orion Multi-Purpose Crew Vehicle (MPCV) on an extended mission to cislunar space. Each of the three launch dates has different launch windows and mission durations:

• August 29th: the launch window runs from 12:33 to 14:33 UTC, and would result in a 42-day mission ending with a splashdown on October 10th.
• September 2nd: the launch window runs from 16:48 to 18:48 UTC, and would result in a 39-day mission splashing down on October 11th.
• September 5th: the launch window opens at 21:12 UTC for 90 minutes, and would result in a 42-day mission splashing down on October 17th.

Splashdown for all three launch opportunities will occur off the coast of San Diego, California.

The dates themselves have been defined based on the need to complete post-Wet Dress Rehearsal  test work on the vehicle. They all represent “long-class” flights for the Orion, with Artmis-1 originally being planned around shorter 4-week flights in order to test out all of its handling characteristics in cislunar space. However, given all of the delays thus far experienced with Artemis-1, NASA opted to push for these launch dates rather wait until the end of October when windows for shorter-during flights would open, together with a further rick of slippage of the launch back into 2023.

Continue reading “Space Sunday: galaxies, launches and health in space” →

The first series of science images from the James Webb Space Telescope (JWST) were released on July 12th, 2022 rightly grabbing the headlines around the world, revealing as they did elements of our universe and our own galaxy in stunning detail and offering a superb launch for the observatory’s science mission.

At the time of their release, NASA also confirmed that, thanks to the extreme accuracy achieved by the European Ariane 5 rocket in delivering the observatory into is transfer orbit which allowed JWST to establish itself in its L2 position halo orbit, 1.6 million km from Earth, sufficient propellants remained aboard the observatory for it to operate for around 20 years – double its original extended mission time.

The mission itself is broken into periods of 12 months apiece, with science institutions, universities, etc., from around the world able to submit papers outlying studies they like to carry out using JWST to the Space Telescope Science Institute (STScI) in Baltimore, USA which form the management and operational centre for both JWST and the Hubble Space Telescope (HST). As such, the initial images selected for release on July 12th represent study targets for JWST accepted for its first year of observational science – but they are not the only targets. Since formally commencing its science programme in June, JWST has already gathered around 40 terabytes of images and data, and following the high-profile release of the initial images, on July 14th, 2022, STScI started issuing raw images of other targets so far examined by the observatory, including images of objects without our own solar system.

Webb is designed to collect light across the entire red to mid-infrared spectrum – wavelengths of light that are blocked by Earth’s atmosphere, and while Hubble crosses from visible light into the near-infrared, JWST has a light collection area 5 times greater than that of HST. Taken together, these facts mean that JWST can reveal objects near and far with a lot more detail than we’ve ever been able to see them, and can also see much further out in the cosmos, allowing us to see the light of objects as they appeared close to the birth of the universe. Add this to the fact that the four science instruments on JWST can be combined to operate in a total of 17 different modes, and JWST is genuinely unparalleled in its capabilities.

The following is a brief summary of the images released on July 12th.

Carina Nebula

Lying some 7,600 light-years away and visible in southern hemisphere skies within the constellation Carina, this nebula (NGC 3372) is a familiar sight among astronomical photographs and studies. It is a massive birth-place of stars, with multiple young stellar groupings like Trumpler 14, and Trumpler 16.

The former, measuring just 6 light-years across (or roughly 1.5 times the distance between our Sun and the Alpha Centauri system) is just half a million years old – but it is home to around 2,000 young stars! Slightly older, Trumpler 16 is home to two of the most luminous stars in our galaxy: Eta Carinae and WR 25. These are two of the most luminous objects in our galaxy – while both are invisible to the naked eye on Earth, they are nevertheless several million times brighter than the Sun.

Neither of these stellar groups was the focus in the Carina Nebula image release on July 12th. This honour went to the “Cosmic Cliffs”, part of a nebula-within-a-nebula (NGC 3324). A ring of dust and debris, it has been formed by the young, super-hot, super-active blue-white stars at the centre of NGC3324 (seen at the top of the image above) generating a collective powerful radiative force that has pushed the remaining gases and dust left over from their formation outwards to a point where the pressure of their own radiation is matched by that of the surrounding larger nebula.

Normally invisible to the naked eye, the portion of the “Cosmic Cliffs” have been beautifully rendered using images from both the Near-Infrared Camera (NIRCam) and the Mid-InfraRed Instrument (MIRI) on JWST, which have been processed to produce a remarkable composite image that reveals never-before-seen details. Within this ring of material, compression and gravity are combining to create even younger stars, many revealed in this image for the first time – with some even showing protostellar jets of material shooting outwards from them. Images like this shed enormous light (so to speak!) on the process of star formation.

Southern Ring Nebula

Catalogued as NGC 3132, the Southern Ring Nebula stands in contrast to the Carina Nebula, being the home of a binary star system where one of the stars is in its death-throes.

The pairing sits in a tight mutual orbit, and the elder of the two stars has gone through a series of events where it has thrown off shells of gas and mass, which are being mutually “stirred” by the two stars as they continue to orbit one another, leading to a complex pattern of gases around both.

JWST imaged the nebula with both NIRCam (seen on the left, above) and MIRI (seen on the right), with the latter showing for the first time that the second star is surrounded by dust, suggesting a more “recent” ejection of mass. The brighter star (visible in both images) is in an earlier stage of its stellar evolution and will probably eject its own planetary nebula in the future.

Studies of phenomena like the Southern Cross Nebula is like watching a slow motion film of a star’s evolution towards the end of its life, each of the shells of gas and dust from outer to inner representing increasingly more recent events in its life, allowing astronomers gain insight in the life and death of stars, whilst studies of the gases released provide insight into how these delicate layers of gas and dust will dissipate into surrounding space.

Stephan’s Quintet

This is a visual grouping of five galaxies, four of which (called the Hickson Compact Group 92) are a genuine grouping of galaxies that are gradually being drawn together by gravity, and will all eventually merge. The fifth member of the quintet is the result of line-of-sight alignment, rather than an actual part of the group. It is possibly best known for its appearance in the classic film It’s a Wonderful Life.

Imaged numerous times in the past, JWST nevertheless reveals the quintet in a new light via a mosaic image that represents Webb’s largest image to date, containing over 150 million pixels and comprising 1,000 individual pictures of the galactic group.

The quartet of galaxies are some 280 million light-years from our own, and of particular note in this composite image is the details of gaseous clouds where star formation is going on; the clear view of the two galaxies in the group which have already collided (UGC 12099 and UGC 12100, now collectively classified as NGC 7318) – the lower right of the “three” close-packed galaxies in the central group – and the white shockwaves of that collision as they sweep towards the top right galaxy, NGC 7319.

Continue reading “Space Sunday: Webb’s views, booster bang + Rogozin’s roulette” →

Our first glimpse through the eyes of the James Webb Space Telescope (JWST) will be unveiled through a live broadcast on Tuesday, July 12th at 14:30 UTC. However, on Friday, July 8th, NASA announced details on what will be featured in the broadcast and the images that will be published during the presentation, promising that the latter will reveal an unprecedented look into some of the deepest views yet of the cosmos.

The targets were selected by an international committee of scientists from NASA, the European Space Agency (ESA), the Canadian Space Agency (CSA) and the Space Telescope Science Institute in Maryland, which manages the observatory. They include:

• The Carina Nebula (NGC 3372): lying some 7,600 light-years away, and visible in southern hemisphere skies, where it appears to lie within the constellation Carina, this nebula is the home of the famous “Pillars of Destruction”, long finger-like structures of cosmic gas and dust.
• Southern Ring Nebula (NGC 3132): appearing to lay within the constellation of Vela (also visible in the southern hemisphere sky) this distinctive nebula of gas and material surrounds dying star is some 2,000 light-years from Earth.
• Stephan’s Quintet: a visual grouping of five galaxies, four of which (called the Hickson Compact Group92) are a genuine grouping of galaxies that are gradually being drawn together by gravity, and will all eventually merge. The fifth member of the quintet is the result of line-of-sight alignment, rather than an actual part of the group.
• WASP-96 b: a “hot Saturn” exoplanet orbiting the star WASP-96, some 1,120 light-years away, within the southern constellation of Phoenix. With a mass roughly half that of Jupiter, the planet orbits its parent every 3.4 terrestrial days and is the first known planet with an entirely cloudless atmosphere, which has a profoundly strong sodium signature.
• SMACS J0723.3-7327: an experiment in using gravitational lensing, using the gravity of relatively “nearby” galaxies to “bend” the light from much more distance galaxies to obtain a deep-field view of their stars.

The presentation and images will mark the first time “operational” data and images relating to scientific targets for the observatory have been made public since the completion of all tests relating to the calibration and commissioning of its four science instruments, all of which allow JWST to operate in a total of 17 different science modes.

It is believed that even though only initial studies of their targets, the images captured by the telescope have stunned science teams and already led to increased understanding of exoplanets, galaxies and the universe itself.

Could Stars be used as Communications Relays?

In June I covered a proposal suggesting the Sun’s gravity could be used to help image exoplanets orbiting other stars using gravitational lensing (see:  Space Sunday: exoplanets, starship and the Sun as a lens). Now a paper accepted for publication in The Astronomical Journal lays out the idea that the lensing effect of the Sun’s gravity, and that of other stars, could be used as some kind of interstellar communications network.

The study discusses the idea that gravitational lensing, involving the bending of light as it passes by massive objects like stars and black holes, could be used to focus communications between one point and another, amplifying the signal like an interstellar cell phone tower.

For the purposes of the paper, a team of students at Penn State University working under Jason Wright, professor of astronomy and astrophysics and the director of the Penn State Extra-terrestrial Intelligence Centre, used the Sun as a model, calculating that the gravitational focus on the solar lensing effect lies some 550 AU out from the Sun – or a distance equitable to roughly half-way between the orbits of Jupiter and Saturn.

This is the point where a communications satellite could be placed such that it could use the Einstein Ring effect of gravitational lensing by the Sun to focus its signals on a distant target – and also receive incoming communications from that target as the Sun’s gravity focuses them down onto the satellite.

The most obvious use of such a system would be to enable communications with deep-space probes we might eventually send to nearby stars (assuming they could be accelerated to reach said stars in a reasonably time-frame). However, the students also noted that if the Sun were to be a part of so alien communications network, then we now have a sphere around it where we might detect any relay, which we might try to eavesdrop on.

Whilst a pretty far-fetched idea in terms of an “alien relay station” sitting in our own back yard, the study does offer some food for thought in how signals from ET (if they exist) might leverage stellar objects, and thus offers a potential new avenue to be explored within SETI and CETI (as in Communications) research.

Exploring Mars by Air: the Case for the Sailplane

The success of the Mars Ingenuity helicopter has been encouraging engineers to consider and reconsider all options for remote aerial observations of the Red Planet over the course of the past year. Additional methods for birds-eye views of Mars would not only provide higher resolution data on the landscapes where rovers can’t go — such as canyons and volcanoes — but also could include studying atmospheric and climate processes that current orbiters and rovers aren’t outfitted to observe.

Once such option that had been considered years ago and is now coming back into focus is that of a sailplane. In particular, students at the University of Arizona have been investigating the possible use of small, relatively lightweight (just 5 kg) unpowered sailplanes that could be carried to Mars as secondary payloads alongside larger missions.

Protected through their entry into the Martian atmosphere, these sailplanes would fall free from their aeroshells to unfold their 3-metre wingspan to use the so-call boundary layer of atmosphere known to exist around Mars and which is of considerable interest to scientists.

You have this really important, critical piece in this planetary boundary layer, like in the first few kilometres above the ground. This is where all the exchanges between the surface and atmosphere happen. This is where the dust is picked up and sent into the atmosphere, where trace gases are mixed, where the modulation of large-scale winds by mountain-valley flows happen. And we just don’t have very much data about it.

– Alexandre Kling, NASA’s Mars Climate Modelling Centre

Potentially also using fully or partially inflatable fuselage, such sailplanes could ride the wind and air pressure, gathering data whilst exploiting atmospheric wind gradients for dynamic soaring to extend their gradual descent to the ground.

Despite their relatively light weight, the students believe the sailplanes would be capable of carrying an array of navigation sensors, a camera system to images the terrain below it, and temperature and gas sensors to gather information about the Martian atmosphere. As a part of their studies, the students have experimented with radio-controlled sailplanes adjusted to fly themselves and which have been lifted to altitude under weather balloons before being released to see how they manage the dynamics of a descent through Earth’s atmosphere.

In addition, the students have used computer modelling to research general vehicle handling within the far more tenuous Martian atmosphere. A particular technique used in sailplaning is to use updrafts and thermals in which a pilot can circle and gain lift to increase altitude. Mars is known to have similar phenomena, and the modelling shows that they could be used in a manner akin to sailplaning on Earth – with the added advantage that the higher effective wind speeds often recorded with such updrafts on Mars have the potential to help carry the sailplanes over much greater distances.

If such vehicles were released over terrain features such as Gale Crater (home of the Mars Science Laboratory rover Curiosity or Jezero Crater, home to the Perseverance Mars 2020 rover, they could be used for detailed high-altitude surveys of the craters, using updrafts as the crater walls to regain momentum whilst mapping the crater floors for surface exploration. However, they could also be used in the first highly-details studies of the nature of Vallis Marineris, the 5,000-km long “Grand Canyon” of Mars.

According to the modelling completed by the students, a sailplane could use the rugged, deep base of the canyon, rich in mesas and plateaus to regularly recover 6-11%  lift energy on a cyclic basis, which together with the higher atmospheric pressure within the canyon system could allow each sailplane to fly for “days”, offering unparalleled opportunities to study this unique environment.

A further attraction with sailplanes is that of cost: development of a suitable glider vehicle could be measured in years rather than decades, utilising common off-the-shelf parts, particularly where instruments are concerned, with most of the effort going into the delivery / deployment system, gaining a better understanding of the Martian atmosphere and its thermal qualities in order to better determine vehicle flight characteristics, and in how to develop the means to recharge the sailplane’s batteries to power its instruments and controls without relying on a potentially cumbersome solar array system.

Currently, the work by the students has been a project largely internal to the university; however, Kling has worked with the team, and he and professor Sergey Shkarayev from the university who has overseen the work, hope that a formal proposal to extend the research might yield NASA funding.

Scientists using data from NASA’s Curiosity rover measured the total organic carbon – a key component in the molecules of life – in Martian rocks for the first time, and have discovered that there is potentially more to be found on Mars than in the driest environments to be found here on Earth.

Organic carbon is carbon bound to a hydrogen atom and is the basis for organic molecules; they are created and used by all known forms of life, and it has been previously detected within Martian rock samples studied by the rover. However, the key difference between those results and those published within this study is that other attempts to examine rock samples for the presence of carbon have only looked for specific compounds that contribute to organic carbon or only represented measurements capturing just a portion of the carbon in the rocks; this study presents the total amount of organic carbon detected in samples gather by the rover during an intensive examination of exposed rock made in 2014.

Total organic carbon is one of several measurements [or indices] that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology. We found at least 200 to 273 parts per million of organic carbon. This is comparable to or even more than the amount found in rocks in very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than has been detected in Mars meteorites.

– Jennifer Stern, NASA Goddard Space Flight Centre, Maryland

To make the measurement, Curiosity delivered the sample to its Sample Analysis at Mars (SAM) instrument, where an oven heated the powdered rock to progressively higher temperatures. This experiment used oxygen and heat to convert the organic carbon to carbon dioxide (CO₂), the amount of which is measured to get the amount of organic carbon in the rocks. Adding oxygen and heat allows the carbon molecules to break apart and react carbon with oxygen to make CO₂. Some carbon is locked up in minerals, so the oven heats the sample to very high temperatures to decompose those minerals and release the carbon to convert it to CO₂. While the samples were gathered and analysed in 2014, it has taken years of ground-based analysis to fully understand the data and to put the results in context of the mission’s other discoveries at Gale Crater to reach a point of being ready for publication.

A specific interest of the study was to identify the carbon isotope ratios. Isotopes are versions of an element with slightly different masses due to the presence of one or more extra neutrons in the nucleus of their atoms. In particular, two of the most common carbon isotopes are Carno-13, with seven neutrons tends to be of largely inorganic origin, while Carbon-12, with six neutrons, tends to be more associated with organic processes – and the study found this to be more abundant than had been anticipated.

But this doesn’t mean that it is absolute evidence that life may have formed on Mars. While the planet was once much warmer and wetter, with a dense atmosphere and free-flowing water on the surface that may have given rise to life, it’s important yo note the “more” used above for Carbon-12 -it can also be the result of non-organic processes such as vulcanism; and Mars was once extremely volcanically active.

Nevertheless, the confirmation that rock samples studied by Curiosity are richer than expected in Carbon-12, coupled with the general environment know to have once existed in Gale Crater – a place that once have an abundance of water and energy sources – further points to the crater being very conducive to life perhaps having gained a toehold there.

Exomoons as the Abode of Life?

We’re all familiar with the Star Wars franchise of films and TV series. In 1977, the original film in the series depicted a rebel base on the fourth moon of the fictional gas giant Yavin.

Many probably didn’t pay much attention to this at the time – beyond noting how the planet played a crucial role in keeping the base shielded from the Death Star, and its cool appearance in Yavin 4’s sky; however, the film was, in many respects well ahead of its time in its depiction of a  habitable Moon. In 1977, the exact nature of moons like Jupiter’s Europa and Saturn’s Enceladus as places of ice and, possibly, water, was suspected rather than known, whilst guesses were also being made about what might lie under the atmosphere of Titan. It would be a couple of decades before we really started to understand the potential for some of the Moons of our outer solar system to have the conditions in which basic life might gain a hold.

While our own solar system moons like Europa are cold place and any life than may form within them sitting within an evolutionary cul-de-sac, the mechanics that make them potentially life-bearing is now being looked at as having the potential to make exomoons like Yavin 4 possible elsewhere in the galaxy.

The major factor in the life-bearing potential of places like Europa and Enceladus is that of tidal forces. In short, as these moons orbit their parents, they are subject to the gravity of the planet exerting a pull on them at the same time as the other moons orbiting the planet also exerting forces on them, all of which causes the moon to “flex”, heating its interior. With Europa and Enceladus, this heating may have resulted un liquid water oceans being possible under their icy surfaces.

Of course, such is the distance between the Sun and these Moons of Jupiter and Saturn than the moons don’t get enough solar heating to remain warm. However, a lot of exoplanets orbit their parent stars a lot closer than our gas giants do to the Sun. While some are clearly too close to their parent, forming what are called “hot Jupiters”, others are at a distance such that any Moons orbiting them could be subject to both tidal action and receive enough solar heating to maintain a potentially temperate atmosphere.

There are question marks around the theory – would such moons be tidally locked with their parent planet, such that the same side of the moon always faces the planet and the same face facing the local star? Would the planet itself be tidally locked to its parent star? How would the atmosphere of a moon fare caught between the outflow of radiation from both star and planet? However, it also promises a new avenue of research for exoplanets and exomoons and the search for signs of life elsewhere in the galaxy, as has been proposed in a paper published in the Astronomical Journal.

What is particularly interesting about the paper is that while the team behind it initially focused on gas giants and their possible moons, their computer modelling suggests that solid rocky planets of the size of Earth or a little bigger / heavier that have Moons could actually become far more habitable themselves.

This is because the majority of Earth-sized worlds, such as those of the TRAPPIST-1 seven-planet system are so close to their parent star so as to be tidally locked, so with one side in perpetual heat and the other in perpetual cold (and darkness), it would be hard for them to offer a foothold for life. However, should such worlds have a reasonably-sized moon orbiting them in a 2:1 resonance, the team’s results showed the planet would itself be far more likely to maintain its own axial spin, thus helping to even-out temperatures across its surface and possibly help maintain an atmosphere.

Thus the importance of exomoons as aiding life, either by supporting it directly or by helping their parent planet remain habitable, has gained further significance, as has the detection of such moons by direct infra-red and spectrographic analysis of their parent worlds by the likes of James Webb Space Telescope and the Extremely Large Telescope.

Walking on the Moon

With humans on the cusp of a return to the Moon, notably via the US / International Artemis programme, a lot of research is going into support systems crews on the Moon will require , such as surface rover vehicles and robot assistants capable of going where astronauts might encounter issues – such as climbing down the steep walls of craters while an astronaut might easily fall.

These robot assistants are being developed by a range of companies and agencies around the world, and one of those with considerable experience in the field is the German Space Agency (DLR). They have come up with a range of small rovers that can operate autonomously or via tele-operation be crews within pressurised environments such as a rover or a base station – or even from orbit.

For the last couple of months, DLR have been testing some of their designs on the upper slopes of Mount Etna, Italy, where the volcanic ash and loose lava is of a similar consistency to lunar regolith. One of the most intriguing of these robots is called Scout, a squat vehicle with a segmented body and which travels not on wheels or tracks, but on rotating “legs” that allow it to “run” over loose ground with relative ease.

Fitted with camera systems and capable of carrying science instruments within its segments, Scout could be used to both  scout for safe routes through difficult terrain than astronauts might then use, and to carry out science functions of its own.

NASA Uses Cygnus to Boost the ISS Orbit

Not long after Russia invaded Ukraine, the head of Roscosmos, Dmitry Rogozin went on a bit of a Twitter / television bender, making a series of aggressive statements regarding Russian co-operation with the United States and the West in the matter of space activates and the International Space Station.

With regards to the latter, one of Rogozin’s claims was that Roscosmos could refuse to use their Progress resupply vehicles to carry out periodic “boosts” to the station’s orbit – required because, even at 450 km altitude, there is still sufficient drag exerted by the very tenuous atmosphere to cause the station to very slowly spiral back towards Earth. Since the US retired the space shuttle, Russia has carried out these boosts using their Progress vehicles. While Roscosmos pushed back against Rogozin’s rants, emphasising continued cooperation with the west with regards to the ISS.

After Rogozin’s threat concerning the required boosts, the US said little, other than noting Progress was not the only option for raising the station’s orbit. In particular, there are two other vehicles with the propulsive capabilities able to perform the task: the Japanese Kounotori HII Transfer vehicle and the American Cygnus craft.

The latter of these performed a proof-of-concept attempt, raising the station’s orbit by 90 metres, but given the use of Progress, nothing further was tried. So, in the light of Rogozin’s comments, and with Cygnus NG-17 docked with the ISS (it had arrived in February 2022), NASA decided to use the vehicle to carry out a required ISS orbital boost.

The first attempt to do so was made on June 20th, but a data hiccup caused the Cygnus vehicle’s motor to cut after just 5 seconds. A further attempt was made on June 25th, with a 301-second engine burn raised the station’s perigee by 0.8 km and apogee by 0.2 km. With the move a success, NG-17 – called Piers Sellers in memory of the Anglo-American astronaut who passed away in 2016 – departed the station on June 28th, loaded with trash and waste from the ISS and performed a controlled re-entry into the denser atmosphere to burn up.

Two new “super Earth” exoplanets have been confirmed as orbiting a star just 33 light-years (10 parsecs) from our own, making them two of the closest rocky exoplanets to Earth to be thus far be located.

Such is their proximity, the planets – HD260655b and HD260655c – offer new opportunities for exoplanet and comparative planetology studies. They both orbit an M-type red dwarf star, the most common  – and one of the oldest – types of star within our galaxy; these stars are both smaller and a lot cooler than main sequence stars like own own, but can also be quite violent in terms of their stellar activity. HD260655 is unusual amongst its brethren as it is somewhat brighter then most other M-type stars, given its comparatively small size. From Earth, it appears to reside within the constellation of Gemini, and is also known by a number of different catalogue designations, including Gliese 239 and Wolf 287.

HD260655b, the innermost of the two planets, zips around its parent at a giddying 2.8 terrestrial days; it is some 1.24 times the size of Earth and has 2.14 times the mass. HD260655c is much more “sedate” in its orbit, taking an entire 5.7 days to go around its parent; it is 1.53 times the size of Earth with around 3.1 times the mass.

The to planets are so close to their parent they are liable to be tidally locked, keeping the same side pointing towards the star all the time, and their estimated temperatures mean they are unlikely to support life: “b” has a temperature of around 435ºC, and likely has no atmosphere (although this is by no means certain), and “c” has an temperature averaging 284ºC – but may have a hydrogen-deficient atmosphere (so no water).

The planets were discovered in a 2021 review of data gathered by the NASA / MIT Transiting Exoplanet Survey Satellite (TESS) mission. Normally the confirmation process for such transiting planets – those that pass between their parent star and the point of observation to produce regular dips in the brightness of their star – can take a lot of additional work, including looking at other data about the star, repeating observations, confirming there has been no instrument error, etc. However, with HD260655, the process was accelerated because it had been tagged as having a possible planetary system in 1998 following observations using the HIRISE (now ANDES) instrument on the Keck telescope, and in 2016 following observations by the  CARMENES instrument at the Calar Alto Observatory in Spain, and the data from these instrument-based observations did much to confirm the presence of both planets.

What is particularly exciting about these two worlds is the combination of their proximity to their star, its brightness and its proximity to our own solar system, all of which makes them ideal for study by the James Webb Space Telescope (JWST).

Among other things, JWST should be able to confirm whether or not either planet has an atmosphere and the composition of that atmosphere. Should it turn out that “b” has no atmosphere but “c” does, it allows for direct observation of the role of their star in characterising each planet over time, and the manner in which M-type stars influence atmospheric loss among their worlds; this in turn allows astronomers to gain a better understanding of the nature of exoplanets orbiting other M-Type stars. Finally, study of HD260655b and HD260655c and comparisons with the rocky planets of our own system could further add to our understanding of how planetary systems in general form.

Starship Update

On June 13th, the Federal Aviation Administration  (FAA) issued its long-awaited Programmatic Environmental Assessment (PEA) concerning the SpaceX Starbase facilities at Boca Chica – and the summary is, neither the FAA nor the other government agencies that were involved in the study have come up with any significant environmental issues that would prevent SpaceX continuing with its current plans with the site.

The report doesn’t, however give SpaceX any immediate clearance to launch their first starship / super heavy orbital attempt. That requires a launch licence, which the FAA has yet to grant – and as a part of that process is that SpaceX demonstrate compliance with 75 action points raised by the PEA. Further, some of the action points will be subject to on-going review and could impact the company’s ability to secure launch licenses beyond the first. Further, the company may yet have to face direct action on the part of environmental groups in light of the fact that activities within the Boca Chica area – also a wildlife refuge – has already impacted some of the rare species living there.

Even so, it currently seems probable the SpaceX could be in a position to make their initial orbital launch attempt with a starship / super heavy combination in August 2022. As it is, the super heavy earmarked for the attempt – Booster 7 – has been equipped with its full complement of 33 Raptor engines, whilst its companion starship, Ship 24, is in the process of being fitted with its engines.

In the next few weeks, we’re liable to see both Booster 7 and Ship 24 return to the launch area, with Booster 7 going through a range of static fire tests on the launch table before being mated with ship 24.

Meanwhile, at Kennedy Space, NASA has finally signalled growing (and, frankly, belated) concern about the SpaceX plans with the Pad 39A facility.

As I’ve previously reported, SpaceX resumed building a second super heavy / starship launch facility within the Pad 39A facilities the company leases from NASA. Of particular concern to NASA is the fact that SpaceX is locating the new launch platform so close to the existing Falcon 9 facilities, that the shockwave from a super heavy launch could conceivably damage the Falcon 9 pad and thus impact NASA’s ability to send crews to the International Space Station.

SpaceX appears to be trying to assuage NASA’s fears in part by installing what appears to be massive water tanks between the new launch facility and Pad 39A, possibly with the intent that the structure deflects sound away from Pad 39A. However, there is a greater threat involved in operating starship / super heavy which has not (in public, at least) been raised by NASA. To understand this threat, we need to go back to July 3rd, 1969.

That was the date on which the Soviet Union attempted to launch the second of its answer to America’s Saturn V, the N1 rocket, from the Baikonur Cosmodrome, Kazakhstan. However, seconds after lift-off the vehicle suffered a major malfunction, crashing back onto the launch pad. On impact, around 15% of the 2,400 tonnes of vehicle propellants detonated in a blast measuring 1 kiloton, obliterating the launch pad and scattering debris up to 10 km away. Fortunately, as the propellants were spread amongst 8 individual fuel tanks across the four stages of the vehicle, 85% did not detonate, but were burned in the ensuing deflagration; had they detonated, the estimated blast yield would have been closer to 7 kilotons – almost half the blast force of the first war time use of an atomic weapon (15 kilotons).

Super heavy doesn’t use multiple tanks. It effectively has two massive tanks that share a common dome (that is, the top end of one tank is the bottom of the other).  This means that in the event of a catastrophic failure, it is exceptionally likely that any detonation will involve the entire 3,600 tones of propellants on super heavy alone, again yielding a blast in excess of 7 kilotons. Such a detonation on the ground or shortly after lift-off would not only level Pad 39A, it could cause at least moderate damage to the launch infrastructure shared by pads 39A and 39B.

Imagining Exoplanets Using the Sun’s Gravity

When it comes to astronomy, gravity can be a very useful tool thanks to the way it can affect light. Back in April, for example, I wrote about the use of gravitational lensing – the bending of light from an object far, far, away by the gravity of an object much closer – to give us our first glimpse of the most distant star from our own to have yet been captured.

The star, now called Eärendel, the Old English term for “morning star” – was imaged by the Hubble Space Telescope using the gravitational lensing effect of an intervening galactic cluster. However, a team led by Slava Turyshev, a physicist at NASA’s Jet Propulsion Laboratory, California, want to take the idea of gravitational lensing to a new level, using our own Sun to image distant worlds.

Turyshev and his team propose the use of a network of small satellites, preferably using solar sails, that could be deployed so as to image exoplanets using a 40 cm telescope in what they call the Solar Gravity Lens (SGL).

The idea has been in development for the last three years, and Turyshev’s team have determined how to resolved many of the idea’s specific problems. One of this is that while the Sun makes an excellent gravity lens, the corona is so bright it actually blots out the Einstein Ring  – the circle of light created by the more distant object – such that it cannot be resolved. To fix this, the team determined that a satellite could, within a solar sail of the right size, use it as both a means of propulsion and effectively cover the Sun and this corona, revealing the Einstein Ring to the telescope. Determining the best size of the solar sail then allowed the team to calculate the mass and size of a satellite – thus allowing them to arrive at the optimal size for the telescope.

From that, the team have been able to work on a series of simulations based on the likely pixel size Earth-sized (or larger) would be produced at various distance up to 100 years years away, which in turn allowed them to simulate how such world would appear after processing their Einstein Ring and then deconvoluting the resultant image.

Further work is required to define the overall carrier spacecraft, but as Turyshev notes, SGL could provide us with insights into worlds beyond our solar system which might otherwise take years or even decades to accumulate.