Two years ago, NASA picked five candidates for future space missions as part of its Discovery program, selecting highly specialized scientific missions for NASA. The each received $3 million to refine their applications, and today . The winners will receive about $500 million in funding to complete their mission, which will take place sometime in the early 2020s.
NASA will give more details beginning at 4pm ET, and you can listen to it live .
Update: NASA has selected Psyche and Lucy as its next two missions. Read about them, and the other runner-up contenders below.
16 Psyche is a metallic asteroid orbiting the Sun inside the asteroid belt, past the orbit of Mars. Psyche is one of the largest asteroids in the belt, and has a unique, mostly metallic composition. Scientists believe that it was once the core of a protoplanet that survived a violent impact with another asteroid.
Psyche's unique composition makes it an ideal target for NASA's next asteroid mission. While NASA's other asteroid missions, OSIRIS-REx and New Horizons, will be studying primarily rocky asteroids, this mission will give NASA scientists a closer look at a metallic one.
"16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core," says Psyche principal investigator Lindy Elkins-Tanton. "We learn about inner space by visiting outer space."
The Psyche mission will give us a chance to get close to a planetary core, and observe it in the state it existed earlier in the Solar System's development. Studying Psyche could tell us more about what our core looked like in Earth's early history,
Beyond the asteroid belt lie a large group of asteroids called Jupiter Trojan asteroids. Jupiter Trojan asteroids are asteroids that , but trail or lead the planet by about a fifth of an orbit. They're trapped in what's called a Lagrange point, an area where the gravitational pull of the Sun and Jupiter cancel each other out.
Scientists estimate that there are as many asteroids located here as in the main asteroid belt, but because they're much further from the Sun we know little about them. Scientists suspect that these asteroids are much older than the main belt asteroids, and studying them closely could give us more information about the early Solar System.
"Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system," says Lucy principal investigator Harold F. Levison.
The Lucy mission would send a probe into the Lagrange point to study six of these Trojan asteroids. This probe would borrow the best tech and personnel from the New Horizons and OSIRIS-REx missions, and will collect brand new data on a class of asteroid we've only ever observed from Earth.
NEOCam is designed to spot and track near-earth objects. NEOs are typically comets and asteroids that have the potential to come close the the Earth and potentially hit it. Because most comets and asteroids are small and dark, they're extremely difficult to spot and sometimes hit or narrowly miss us with little or no warning. NEOCam would be able to increase the number of detected NEOs tenfold.
The VERITAS mission would produce high-definition topographical maps of Venus' surface. Venus is covered in thick clouds and haze, so it's difficult to map the surface of the planet from space, and the high pressures and corrosive atmosphere make it nearly impossible to land a probe on the surface. The VERITAS probe would be equipped with special cameras and sensors to see through the thick atmosphere and actually image the surface.
Another Venus mission, DAVINCI, would study the composition of Venus' atmosphere. DAVINCI would be a short-lived mission, slowly descending to the surface over the course of an hour. Along the way, the probe would continuously sample the planet's atmosphere, and the data it collects would be used to answer questions about Venus like whether the planet has any active volcanoes.