Asteroids are some of the most ancient objects in the Solar System, relics left over from the time when the planets first started forming and evolving. For this reason, scientists are very interested in them, since they can provide clues as to how this process occurred. Most asteroids orbit the Sun in a broad belt between Mars and Jupiter, but they can be found elsewhere in the Solar System as well. NASA’s OSIRIS-REx spacecraft is now en route to one of these asteroids, called Bennu, which it will study and then bring a sample back to Earth. While on the way there, however, OSIRIS-REx will also be searching for other asteroids, called Trojans. These have regular orbits which place them either just before or just behind a planet, including Earth. The spacecraft will be on the lookout for some of these Trojans near Earth this month as it travels toward Bennu.
NASA has chosen two new missions to explore the Solar System; it was announced today during a media teleconference. The missions are part of NASA’s Discovery Program, and after the competing proposals had been narrowed down to five contenders, the final two winners were announced. Both missions, called Lucy and Psyche, will visit asteroids which have never been seen up close: multiple Trojan asteroids which share Jupiter’s orbit and the unusual metal asteroid 16 Psyche. These missions will study such objects which are relics left over from the early beginnings of the Solar System, providing new clues as to how the planets and other bodies formed. Two other mission proposals to return to Venus did not make the cut, unfortunately.
Sending human astronauts to Mars is a dream shared by many, but there are still challenges to overcome and the question of just how to accomplish it is a subject of intense debate. Some supporters advocate sending a mission directly to Mars, while others think that returning to the Moon first, for potentially beneficial training, is the way to go. Indeed, former astronaut James Lovell, who flew on two trips to the Moon, has also called for a return to the Moon first. NASA itself has stated its desire to send a crewed mission to a nearby asteroid first, instead of the Moon, going a bit farther into space than the Moon as its idea of preparation for the much longer journey to Mars. A major problem has been that NASA has still not set a firm timetable for such a mission; it wants to go to Mars, but the steps to achieving that goal are still unclear.
This coming September, a new NASA spacecraft, OSIRIS-REx, will be heading toward an asteroid to collect samples which will later be brought back to Earth. This is the first time for such a sample return mission to an asteroid by a U.S. spacecraft, but there’s also another unique aspect to this mission – artists, and space enthusiasts in general, are being invited to submit some of their work to be included onboard the spacecraft.
Looking ahead to future planetary missions, NASA has selected five new science investigations for refinement over the next year. Later, one or two of those missions will be chosen to actually be launched, perhaps as early as 2020. The selections are part of NASA’s Discovery Program, which had requested the proposals in November 2014. Initially, 27 proposals had been submitted, from which the five current finalists were chosen. The five proposals would study Venus, near-Earth objects, an unusual metallic asteroid and Trojan asteroids.
Near-Earth asteroids, also known as Near Earth Objects (NEOs), are some of the best studied space rocks in the Solar System, primarily due to the fact that they approach the orbit of Earth, making them potentially dangerous to our home planet. Now, a new study has provided evidence that at least some of them, including dark ones which are more difficult to see, originate from the oddball Euphrosyne family of dark asteroids which are at the outer edge of the main asteroid belt between Mars and Jupiter, but have highly inclined orbits well above the plane or “equator” of the Solar System.
The Dawn spacecraft left behind the giant asteroid Vesta last September, and is now en route to the even bigger dwarf planet Ceres, but scientists are still busy studying all of the data that was sent back to Earth while it was orbiting Vesta for over a year. And as often happens while exploring these new worlds, they have made a surprising discovery: long, sinuous gullies on the walls of geologically younger craters.
With all of the news lately about the landing of the Curiosity rover on Mars, it might be easy to forget about the other missions currently going on all over the solar system. That includes the asteroid belt, where the Dawn spacecraft has been orbiting and studying the giant asteroid Vesta since July of last year, sending back incredible photos and information about this unique world.
But now, Dawn has departed from Vesta to continue its mission elsewhere; on September 4, it escaped Vesta’s gravitational pull and is now headed for its next rendezvous – the dwarf planet Ceres. It is expected to arrive there in early 2015, the same year that the New Horizons spacecraft will finally reach Pluto.
See Examiner.com for the full article.
In 2010, the Japanese spacecraft Hayabusa completed an exciting although nail-biting mission to the asteroid Itokawa, successfully returning samples to Earth after first reaching the asteroid in 2005; the mission almost failed, with the spacecraft plagued by technical problems. The canister containing the microscopic rock samples made a soft landing in Australia, the first time that samples from an asteroid had been brought back to Earth for study.
Now, the Japanese government has approved a follow-up mission, Hayabusa 2. This time the probe is scheduled to be launched in 2014 and rendezvous with the asteroid known as 1999 JU3 in mid-2018. Samples would again be taken and returned to Earth in late 2020…
See Universe Today for the full article.
Vesta, while one of the largest asteroids, is still a lot smaller than Earth, and yet it has a mountain that is three times taller than Mt. Everest, reaching about 22 kilometres (13 miles) in height. It sits inside the huge south polar crater, so is similar to many other craters on various planets and moons which have central peaks. It is surprising nonetheless to see such a large mountain on a relatively small body like Vesta, especially since it is so much higher than the tallest mountain on Earth!
The included image, taken by the orbiting Dawn spacecraft, shows a perspective view of the topography, but without the curvature of Vesta, as if you were looking at it standing on a flat Vesta instead of rounded. The resolution is about 300 metres (1,000 feet). The additional slideshow images show various views of the mountain. There is also a large steep-sloped scarp which bounds part of the south polar crater.
There will be a news conference on Wednesday, October 12 at 10:00 a.m. PDT to discuss the latest results from Dawn, to be held at the Annual Meeting of the Geological Society of America, in Minneapolis. It can be watched live on the Geological Society of America web site and on Ustream, which includes a moderated chat.
This article was first published on Examiner.com.