For a long time now, there has been growing interest in sending a mission back to Jupiter to better study one moon in particular: Europa. Previous missions such as Voyager and Galileo showed us this world up close for the first time, revealing a place that maybe, just maybe, is home to some kind of life. On the outside, Europa is cold and frozen, like an airless version of Antarctica, with its surface completely composed of ice. But deeper down, as those probes found, there is a global ocean of water deeper than any oceans on Earth. In more recent years and months, a new NASA mission to Europa has finally started to take shape, with a launch tentatively scheduled for 2022. As often happens, however, the mission is facing possible budget cuts in 2017.
The Curiosity rover is continuing to travel through the ancient and eroded buttes and mesas which are part of the Murray Buttes formation. Very reminiscent of the terrain in the desert regions of the American southwest. Included are a couple new panoramas, processed by Thomas Appéré. All images are available on the mission website.
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.
For the most part, the Solar System seems to be a rather well-ordered place; the planets, dwarf planets, and asteroids keep circling the Sun in regular orbits, the moons keep orbiting the planets, and so on. There are exceptions, however, such as how Uranus rotates “on its side” as compared to other planets and how Venus rotates in the opposite direction to most other planets. Now, astronomers have discovered another similar oddity, in the outer fringes of the Solar System: a small, asteroid-like object whose orbit is not only highly tilted against the orbital plane of the planets, but is also orbiting backwards compared to them. And it’s not alone. It appears to be part of a larger group of objects all doing the same thing. Weird…
The Curiosity rover has been sending back some beautiful images of the Murray Buttes which it has now reached, near the base of Mount Sharp, on Mars. There are many buttes and mesas in this region, including in the foothills of the mountain itself. The current header graphic for the blog is also part of a new panoramic image of the buttes, processed by James Sorenson. All images are available on the mission website.
July 20, 1976, will be forever remembered by space enthusiasts. On that day, Viking 1 became the first U.S. spacecraft to land on another planet – in this case, Mars (the USSR Venera 9 spacecraft landed on Venus in 1975). That lander, and Viking 2 which followed it Sept. 3, 1976, paved the way for more complex missions later on, which would begin to finally unlock some of the secrets of the mysterious Red Planet. The two Viking landers, and their counterpart orbiters, were genuine trailblazers, opening up the vast Martian landscape to robotic and human eyes for the first time.
The Solar System is a busy place, with spacecraft currently visiting most of the planets as well as some dwarf planets and comets. Akatsuki is at Venus, several rovers and orbiters are at Mars, the Juno spacecraft just reached Jupiter, Cassini is still orbiting Saturn, Dawn is still at Ceres, and Rosetta continues to study the comet 67P. Mercury, Uranus, Neptune, and Pluto have all been visited by previous missions as well. But there is one other place in the Solar System which will also be explored more closely in the near future: the Sun.
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.
Jupiter has often been referred to as the King of Planets, and for good reason, as it is a massive gas giant, much larger than Earth and the largest planet in our Solar System. It is more than 2.5 times as massive as all the other planets combined, and is a mesmerizing world of colourful bands of clouds wrapping around the globe, which can be seen even in a small telescope, but exhibit incredible detail when seen by spacecraft. Jupiter is also itself the center of a sort of miniature solar system, with dozens of moons orbiting around it. We’ve seen this world up close before by spacecraft such as Voyager and Galileo, but now a new visitor has arrived in the Jovian system: NASA’s spacecraft Juno.
So-called “waterworlds” have been found to be surprisingly common in the Solar System – small icy moons which have ice crusts but oceans of liquid water below the surface. These include Jupiter’s moons Europa and Ganymede and Saturn’s moons Enceladus and Titan, and possibly others. These moons are cold and very far from the Sun, but heated inside by the gravitational pull of their giant host planets and/or radioactivity. Now there’s another Solar System body which, even more surprisingly, some scientists think has a subsurface ocean: Pluto.