Space Sunday: Webb’s views, booster bang + Rogozin’s roulette

Where they are: the five subjects of the first five science images release by NASA for the James Webb Space Telescope (JWST). 1: the Carina Nebula; 2. the Southern Ring Nebula; 3. Stephan’s Quintet; 4. WASP-96b; 5. SMACS 0723. Credit: NASA/Goddard Space Centre / STScI
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.

The “cosmic Cliffs” of NGC within the Carina Nebula, showing the blue “bowl” of hot stars that have pushed interstellar dust and gases into to a ring that resembles towering cliffs and mountains, and within which younger, new stars can be seen. Credit: NASA/Goddard Space Centre / STScI

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.

The Southern Ring Nebula as seen by JWST’s NIRCam (l) and MIRI (r). Credit: NASA/Goddard Space Centre / STScI

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.

Stephan’s Quintet, comprising a close-knit group of four galaxies, two of which have already merged (centre right) to form NGC 7318. Also visible in the image are clouds of sat-forming dust and material, and the shockwave of the NGC 7318 merging rippling through NGC 7319. Credit: NASA/Goddard Space Centre / STScI

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.

WASP-96b

WASP 96b is a “hot Saturn” exoplanet orbiting the star WASP-96 (the acronym standing for Wide Angle Search for Planets, a pair of Earth-based observatories in the Canary Islands and South Africa dedicated to locating exoplanets), some 1,120 light-years away, and with a mass roughly half that of Jupiter.

Orbiting its parent every 3.4 terrestrial days, the planet has been previously studied using transmission spectroscopy (gathering the light from the parent star both before and during a transit of the planet between the star and Earth), to determine which wavelengths of light are absorbed by its atmosphere, thus revealing the chemical composition of its atmosphere. Those observations, carried out independently by the Very Large Telescope  in 2018 and later by the Magellan Telescopes, indicated high concentrations of sodium in the planet’s atmosphere, suggesting it to be cloudless.

On June 21st, 2022, Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) measured light from the WASP-96 system for 6.4 hours as the planet moved across the star. The result shows water to be present in the atmosphere, together with indications of cloud and haze, contradicting previous observations of the planet’s atmosphere, and thus providing JWST’s first mystery. Credit: NASA/Goddard Space Centre / STScI

However, Webb’s transmission spectroscopy appears to reveal the presence of water molecules in WASP-96b’s atmosphere, as well as evidence for clouds and a hazy sky, and these contradictory results are proving to be a surprising puzzle for astronomers, who are reanalysing both the Webb observations and the previous optical observations to better understand the behaviour of WASP-96b’s atmosphere and the relationship between its molecular composition and its cloud levels. That said, the presence of water in the planet’s atmosphere does not mean it is likely to be in any way habitable – it is a gas giant, and a very hot one at that, given its proximity to its parent star.

SMACS 0723

This is perhaps the most remarkable of the initial Webb images released on July 12th. It reveals both the galaxy cluster SMACS 0723, and galaxies even further away, brought into focus by the “lensing” effect of the cluster itself.

Produced by the NIRCam system on Webb, the image represents multiple images of the cluster taken at multiple IR wavelengths over a period of 12.5 hours. These images were then composited together into the picture shown here, revealing SMACS 0723 as it appeared some 4.3 billion years ago, when the light from the cluster first set out, and the light from more distant galaxies and stars that started out billions of years before that, allowing astronomers to effectively look back in time as far as perhaps just a billion years after the Big Bang started everything.

SMACS 0723 as it appeared 4.6 billion years ago, with many more galaxies in front of and behind the cluster. The like radiating out from some of the stellar objects is the result of image artefacts; the blurring of some of the more distant objects is the result of the gravitational lensing effect of the SMACS 0723. These objects are much further away from Earth and JWST then SMACs, and so represent galaxies formed much earlier in the history of the universe. Credit: NASA/Goddard Space Centre / STScI

However, what is probably the most remarkable fact about this image is that it represents a portion of the universe equal in size to a grain of sand held at arm’s length from the naked eye!

As well as being imaged by NIRCam, the cluster was also captured by MIRI, with the raw images just starting to be made available as this piece was being prepared. In addition Webb also obtained spectra on many of the galaxies in the cluster which can reveal much of the chemical properties they contain, so helping astronomers understand more about their stellar composition.

A unique facet with the observatory is that it can use its Near Infrared Spectrograph (NIRSpec) microshutter array to simultaneously observe over 40 galaxies at a time within a cluster like SMACS 0723, and gather a full suite of date on each of them!

Super Heavy Booster 7 In launch Stand Explosion

On July 11th, 2022, the SpaceX Starbase launch facilities at Boca Chica, Texas were rocked by an unexpected explosion during what was supposed to be a “simple” spin start test of an unspecified number of the Raptor 2 motors on the massive Booster 7 rocket expected to form part of the first orbital attempt by a SpaceX Super Heavy / Starship combination some time in the next month or so.

A spin start test involves running up a rocket motor to the point of ignition. It is designed to confirm the engines are functioning as expected, with turbo pumps initiating and fuel being fed into them, but with everything stopping short of actual engine ignition.

Exactly what happened has yet to be fully defined, but it appears a heat source or spark ignited methane being vented from the base of the rocket immediately prior to the spin start. Where cryogenic propellants are used, pad systems tend to include small burners that prevent gasses accumulating by rapidly burning them off immediately prior to rocket motors being spun-up. SpaceX does not appear to have considered this – but statements since the accident suggest they now will.

Following the explosion and initial fires, a smaller fire was spotted at the base of the pad, which lead to additional precautions being taken in order to “safe” the rocket. The remaining liquid methane was de-tanked using the upper fuel feed system, suggesting the propellant feed system at the base of the launch platform had been damaged – although once the methane had been de-tanked, the liquid oxygen was unceremoniously dumped directly through the booster’s 33 Raptor engines.

The degree of damage to the Booster was unclear, but on Thursday, July 14th, it was rolled back to the production area for inspections / repairs. Immediately after its return, Musk suggested on Twitter that the booster could be back on the launch stand in a wee; which frankly seems a little optimistic.

Surprisingly, the FAA, while in contact with SpaceX following the explosion, have indicated they will not actually be investigating it, apparently because the test was not intended to go as far as engine ignition.

 Rogozin’s (Space) Roulette

It’s been another interesting week in Russia-West space relations that smacks of Russia playing a game of roulette.

Russian President Vladimir Putin (centre) and Roscosmos chief Dmitry Rogozin (right) pictured in April 2018, just before Putin appointed Rogozin to head Roscosmos. Credit: Kremlin.ru

On July 8th NASA and its international partners – a total of 15 nations – publicly rebuked Russia for playing “political propaganda! on the ISS after Roscomos released images of cosmonauts Sergey Korsakov, Oleg Artemyev and Denis Matveev apparently joining-in with ground-based organised celebrations to mark the fall of the city of Lysychansk to Russia invasion forces by holding flags associated with the self-proclaimed Luhansk People’s Republic and Donetsk People’s Republic – whose independence from Ukraine is recognised by only Russia and Syria.

Then on July 12th, the official ending of cooperation on space efforts between Russia and the European Space Agency came into effect – leading to Roscomos chief Dmitry Rogozin once again taking to Telegram in a series of rants. These included an order to the Russia crew on the ISS to cease work on a new European-built robot arm mounted on the Russian Nauka module and primarily intended to help operations on the Russian side of the station.

On July 15th, Rogozin was more conciliatory, joined with NASA in confirming that a seat bartering arrangement had been reached by which US Astronauts will continue to fly to the ISS aboard Russian Soyuz craft as and when required, and Russian cosmonauts will be given seats aboard US vehicles, starting with Anna Kikina, who will fly on the Crew-5 mission due to launch in September 2022.

And if that wasn’t enough, that same day, Vladimir Putin removed Rogozin as the head of Roscosmos. In part this appears to be in response to Rogozin’s inflammatory statements over the past several months – but it shouldn’t bee seen as a condemnation; rather Rogozin’s outspoken support for Putin’s foreign policies appear – according to Russian media –  to have caused Putin to consider Rogozin for his next Chief-of-Staff. In the meantime, Yuri Borisov, most recently Russia’s Deputy Prime Minister – a role Rogozin also held in the past.

 

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