Some of the most interesting exoplanets discovered so far are the “super-Earths,” rocky worlds which are significantly larger and more massive than Earth but still smaller than the ice giants such as Uranus or Neptune. Since they are not present in our own Solar System, their existence elsewhere can provide valuable information about planetary formation processes around other stars. One of the most significant aspects of this is the detection of water vapor in the atmospheres of these or other exoplanets, as this can help astronomers determine which super-Earths, or other exoplanets, may also have liquid water and be potentially habitable.
Category Archives: Exoplanets
The search for exoplanets is about to enter an exciting new phase, as the Transiting Exoplanet Survey Satellite (TESS) mission has now been cleared for development by NASA. TESS will greatly expand the number of stars being observed for evidence of exoplanets orbiting them, as the next step forward from the Kepler space telescope and others which have already found thousands of such worlds outside of our own Solar System.
Comets have been in the news a lot recently, with the ongoing investigation of comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft and the close flyby of Mars by comet Siding Spring this past week. But there is also another comet discovery – one much further out from our solar system. With the help of the HARPS instrument, on the European Southern Observatory’s (ESO) 3.6-meter telescope, astronomers have identified nearly 500 comets orbiting the nearby star Beta Pictoris, as part of an unprecedented new survey of exocomets orbiting other stars.
Many different kinds of exoplanets have been found by astronomers, from giant “hot Jupiters” and “super Earths” to smaller rocky worlds like Earth or Mars. Now, another type has been discovered, an “ice giant” similar to Uranus or Neptune in our own Solar System. The planet is about 25,000 light-years away in the constellation Sagittarius and is one of the first found that appears to be similar to the ice giant planets in our Solar System, Uranus and Neptune, which are part gas and part ice in composition. The discovery was made by an international team of astronomers, led by Radek Poleski, a postdoctoral researcher at Ohio State University.
Being able to find exoplanets orbiting distant stars is a major accomplishment in itself, and fine-tuning the data enough to discover details about the characteristics of those planets is quite another. Not an easy task. Astronomers have had some initial success, but now they have been able to create the most detailed weather map for any exoplanet so far.
Solar systems, including ours, are thought to begin as massive clouds of dust and gas surrounding young stars; over billions of years, planets form from repeated impacts of rocky debris. Asteroids and comets are left-over chunks of debris from that process which didn’t coalesce together. Such debris clouds, or protoplanetary disks, have been found around many young stars. These are solar systems still in their infancy. Now, astronomers have been able to observe the actual collision between two large rocky bodies, most likely asteroids, in a protoplanetary disk surrounding a young, Sun-like star 1,200 light-years away.
Astronomers have discovered the oldest known (so far) exoplanet which might be capable of supporting life; the planet, Kapteyn b, is likely more than twice the age of the Earth. The planet was found by an international team of astronomers, led by Guillem Anglada-Escude from Queen Mary University.
Astronomers on Monday made a “big” announcement about exoplanets, and it is big – literally. Another new world has been discovered, which is quite routine now these days, but this one is different, and unexpected; a planet which is more than twice as large as Earth and about 17 times heavier, a sort of “mega-Earth” as some have referred to it. Nothing else like it has been seen before, until now. The new discovery was announced at a press conference during a meeting of the American Astronomical Society (AAS).