The seven Earth-sized exoplanets orbiting the star TRAPPIST-1 generated a lot of excitement when their discovery was announced last month. This is the largest collection of Earth-sized worlds in one planetary system found so far, and some of them are well within the star’s “habitable zone” where temperatures could allow liquid water to exist on their surfaces. Little else is known about the actual conditions on these planets so far, but NASA’s Kepler Space Telescope has also been observing TRAPPIST-1 in recent weeks.
The discovery of seven Earth-sized planets orbiting the star TRAPPIST-1 generated a lot of excitement last week. Earth-sized planets have been found before, among the thousands of exoplanets discovered so far by astronomers, but this is the first time that so many have been detected in one planetary system. As of now, astronomers are limited in how much they can learn about these new worlds, but the James Webb Space Telescope, the upcoming successor to Hubble due to launch in 2018, will be able to gather more data and analyze whatever atmospheres these planets have, perhaps bringing us closer to finding another habitable world.
The search for exoplanets – planets orbiting other stars – has been one of the most exciting developments in astronomy and space science in recent years. The first couple exoplanets were found in 1992, and now over 3,400 have been confirmed, with over 5,000 additional candidates. Some of these are smaller rocky worlds similar in size to Earth, bringing scientists close to finding “Earth 2.0” – another planet with water and, perhaps, life. Yesterday, NASA announced another key discovery, bringing us even closer to finding another living world – a star with not just one or two Earth-sized planets orbiting it, but seven. Three of those planets are in the star’s habitable zone, where, depending upon other surface conditions, lakes or oceans of liquid water could exist.
The Kepler K2 mission has now resumed after a delay of three days, NASA has reported. The Kepler Space Telescope is currently in Campaign 11, during which it is observing a total of 14,250 new targets, including the Galactic Center as well as two of Saturn’s moons, Enceladus and Titan.
Now that we know the closest star system to us has at least one planet, an Earth-mass and potentially habitable one at that, there is one big question a lot of people are asking: Can we go there? Could we send a probe to Proxima Centauri? The answer is… maybe. There have long been ideas and plans for such a mission, but now that at least one planet has been verified there, interest is at an all-time high. It’s doable, but not necessarily easy.
Astronomers today announced one of the most exciting exoplanet discoveries yet: an Earth-mass rocky world orbiting the nearest star to the Sun, Proxima Centauri. There had been hints before of such a world, but nothing was confirmed, until now. The planet, called Proxima b, is not only just slightly more massive than Earth, it orbits within the star’s “habitable zone.” The estimated temperatures of the planet could allow liquid water to exist on its surface. Not only is this planet potentially habitable, depending on other factors, it is also now the closest known exoplanet.
Over the past couple decades, astronomers have been discovering a seemingly endless variety of exoplanets orbiting other stars. Some are rather similar to planets in our own Solar System, while others are more like ones depicted in science fiction, ranging from rocky worlds about the size of Earth and larger, to massive, searing hot planets larger than Jupiter orbiting very close to their stars. Tatooine is another well-known example – the desert planet orbiting two suns in the Star Wars films. Now astronomers have found a similar world, using direct imaging, but which orbits within a system of three stars.
For several years now the Kepler Space Telescope, as well as other telescopes, has been discovering an increasing number of exoplanets, with over 2,000 such confirmed worlds found so far (and nearly 5,000 candidates). Today, NASA announced that the Kepler mission has added 1,284 newly confirmed exoplanets to that list, vastly increasing the number of known planets orbiting other stars. This is the largest number of new planets ever announced at one time. The new results were announced during a NASA teleconference briefing.
Exoplanets are now being discovered by the thousands, but most are so far away that determining anything specific about their composition or atmosphere is currently very difficult. But technology keeps advancing, and scientists are now starting to be able to learn more about them, at least ones which are a bit closer to our own Solar System. One of the most common types of exoplanets are the “super-Earths,” which are larger and more massive than Earth but smaller than Uranus or Neptune. Now, astronomers have been able to analyze the atmosphere of one of these worlds for the first time.