For about the past 30 months, the Opportunity rover has been exploring Cape Tribulation on Mars, a towering ridge on the rim of Endeavour crater. Now, Opportunity has finally left that location, to continue its journey southward down the western side of the crater rim. The views have been scenic from the top of Cape Tribulation, but now it is time to move on, and head to the next major target, an ancient gully not too far to the south-east, also on the crater rim. This gully is thought to have been carved by running water millions or billions of years ago, so scientists are very interested in examining it up close, and the rover is now almost there.
Just recently, an exo-planetary system called TRAPPIST-1, with seven known planets close in size to Earth, was announced by astronomers. Some of those planets are in the star’s habitable zone, meaning that they could potentially be habitable for some kind of life. Then, another Earth-sized world was found orbiting the star GJ 1132b, and may have water and methane in its atmosphere. Now, another similar planet has been found orbiting another nearby star. It is also close in size to Earth and resides in the star’s habitable zone. According to scientists, it is another prime candidate in the search for alien life and may even be the best one yet.
This week marks another important milestone in the Cassini mission at Saturn – as of today, the spacecraft is conducting the last Ring-Grazing Orbit of its mission as it prepares for the Grand Finale, which will culminate in the death of the probe on Sept. 15. On April 21, Cassini will do its very last close flyby of Saturn’s largest moon Titan. Speaking of Titan, Cassini has also apparently solved a perplexing mystery; the unusual “magic island” formations seen in one of the moon’s methane/ethane seas are now thought to be caused by nitrogen bubbles fizzing periodically on the sea’s surface.
There is an interesting new paper out about the seven near-Earth-sized exoplanets orbiting the star TRAPPIST-1. According to the study, four of the planets may be true water worlds, although just what form those may take isn’t clear. All seven planets are close in size to the Earth, with some of them in the star’s habitable zone, where temperatures could allow liquid water on rocky surfaces.
For those who are hoping to find evidence of life somewhere else in the Solar System, there was some exciting news this week. Two moons, Europa and Enceladus, were already thought to be among the best places to search, since both have liquid water oceans beneath their outer icy shells. And now, new data from the Cassini spacecraft and the Hubble Space Telescope has increased the potential for some form of living organisms to be found.
Some great new views from the Cassini spacecraft of Saturn’s tiny moon Atlas were released today. Atlas is similar to another Saturnian “ravioli” or “flying saucer” moon, Pan – a central roughly spherical or oblate body with an unusual broad equatorial ridge. Like Pan, the ridge is thought to have formed from material coming from Saturn’s rings, and also like Pan, the ridge on Atlas appears very smooth, but is significantly larger. Atlas orbits just outside the outer edge of Saturn’s A ring and is very small, only about 15 kilometres (9.4 miles) across, but still larger than Pan.
For the first time, astronomers have detected an atmosphere surrounding a “super-Earth” exoplanet which is close in size to Earth, another key step towards finding a world similar in size to ours that is also habitable. It’s not Earth 2.0 just yet, but it’s another indication that we are getting closer to finding a world that reminds us of home.