The Kepler Space Telescope might be shut down, but the work of analysing the data it gathered on possible exoplanets continues, and an international team of scientists reviewing some of the earliest data from the mission have confiemd what had been thought of as a “false positive” is in fact an Earth-size exoplanet orbiting within its star’s habitable zone, the area around a star where a rocky planet could support liquid water.
The planet, Kepler-1649c orbits its small red dwarf star some 300 light years from Earth. It is so close to its parent, that its year is the equivalent to 19.5 Earth days. It is actually the second planet to have been found orbiting the star, hence the “c” designation in its name, and the system as a whole contains a series of points of interest for astronomers that make it particularly intriguing.
The first is that the data Kepler gathered on the planet suggest it is one of the closest in terms of size to Earth so far discovered, being just 1.06 times larger. The second is that its parent, Kepler-1649, is a class-M red dwarf with relatively low luminosity, so that despite it’s close proximity, that planet receives around 75% of the sunlight Earth receives from Sol. so it is entirely possible that if it has an atmosphere, conditions on it surface might be somewhat similar to our own in terms of average temperatures and with regards to surface water.
However, whether the planet does have an atmosphere has yet to be determined. As I’ve previously noted in this column, red dwarf stars are so small they rely on convection as the main form of energy transport to the surface, and this can give rise to violent solar outbursts which over time can rip away a nearby planet’s atmosphere. There’s also the question of how stable any atmosphere might be. Again, its close proximity to its parent means it is liable to be tidally locked, always keeping the same face towards its star. This is liable to make any atmosphere the planet does have could be exceptionally turbulent and prone to storms along the terminator dividing the light and dark halves.
However, Kepler-1649 has thus far shown itself to be one of the more stable M-class stars that has been observed over the years from Earth – which means it may well still possess a temperate atmosphere. If this is so, the combination of size and atmosphere then of all the red dwarf orbiting exoplanets thus far discovered, Kepler-1649c could be closer to Earth than most so far discovered.
An additional intrigue with the Kepler-1649 system is that the two planets share an unusual orbit resonance: for every nine times Kepler-1649c orbits its parent, the inner planet, Kepler-16949b, orbits almost exactly four times, giving a 9:4 ratio. This indicates the system is extremely stable, likely to survive for a long time.
9:4 is also something of a unique ratio; usually resonances take the form of ratios like 2:1 or 3:2. As such, it is thought that the Kepler’s system’s resonance might be indicative of a third planet between Keplert-1649b and Kelper-1649c, which would give the system a more regular pairing of 3:2 resonances between the middle and inner planets and the middle and outer planets. However, the existence of any third planet has yet to be confirmed.
In the meantime, the discovery of Kepler-1649c adds significantly to our understanding on exoplanets around M-class stars.
The more data we get, the more signs we see pointing to the notion that potentially habitable and Earth-size exoplanets are common around these kinds of stars. With red dwarfs almost everywhere around our galaxy, and these small, potentially habitable and rocky planets around them, the chance one of them isn’t too different than our Earth looks a bit brighter.
– Andrew Vanderburg, co-author of a paper on Kepler-1649c exoplanet
Curiosity: A New Level of Remote Working
As the SARS-CoV-2 virus continues to prevent us from working normally, members of NASA’s Mars Science Laboratory Curiosity team have revealed how they’ve been continuing with normal operations since the Jet Propulsion Laboratory (JPL) shut down operations in February 2020.
Of course, in some respects the rover team has always been working remotely from their “office”, the rover never being at least 56 million km from Earth. However, the shut-down of NASA facilities ordered by Administrator Jim Bridenstine brought additional challenges to operating a rover so far away – and I’m not talking about distractions caused by the need to feed the cats or take the dog for a walk, being reliant on e-mail and video conferencing, etc.
Take driving the rover, for example. This requires a complex process of scanning the rover’s surroundings to build up a complete view of the rover’s environment, having the means to view this in 3D and to compare it to high-resolution images of the rover’s surroundings captured from orbit, then mapping a potential route that avoids any aspects of the landscape that present a risk to the rover whilst also encompassing points of interest, converting the commands into software code, testing it, and finally transmitting it to the rover for execution. Similarly, manoeuvring and using the rover’s robot arm requires precision and care, rehearsal and coding.
Much of this work requires high-powered computers. Analysing potential route from images, for example, requires not only high-resolution image processing, but also high-end gaming PCs and 3D headsets to give a greater depth of field and better visualisation of contours of the landscape and rocks. A similar approach is used to manoeuvring and manipulating the robot arm. The problem is, not all of the systems required to achieve all of this could easily be transitioned from JPL’s facilities to home use. Teams are, for example, restricted to using laptops, rather than gaming PCs; they’ve therefore had to swap from using specialised 3D headsets that rapidly shift between left- and right-eye views to better reveal the contours of the landscape, and instead rely ordinary anaglyph glasses to achieve the same ends.