view Vesta dawn at a distance of 41,000 km space agency says its probe Dawn must enter into orbit around the asteroid Vesta early Saturday (GMT).The robotic satellite will be a year in 530 km – whole body before moving on to the "dwarf planet" Ceres.
New photos in the approach of dawn Vesta show the giant rock in unprecedented detail.
The asteroid appears a football punctured, the result of a colossal collision at some point in their past that struck the region of the South Pole.
Vesta was discovered in 1807, the asteroid fourth to identify large belt of rocky debris orbit between Mars and Jupiter.
At the time, their large scale means he was appointed as another planet but later lost this status as researchers learned more about the diversity of the objects in the Solar System.
Close but bewareDawn encounter is producing about 188 million kilometers (117 million miles) of the Earth.
The spacecraft is propelled by an engine of ions and engineers have the spacecraft on course to be caught in the gravitational field of Vesta.
They expect to hear confirmation from the satellite on Saturday which is hanging around the rock.
Initially, Dawn will be approximately 16,000 miles (9,900 km) from the asteroid, but this distance will be reduced over time.
The mission scientists hope within 200 km of the surface, but the team did not want to take unnecessary risks.
"We would like to obtain lower possible, but if we crash Dawn, Nasa would understandably be very angry with us", main researcher Chris Russell told BBC News.
Asteroids can tell us about the early days of the Solar System. Wandering rocks are often described as the rubble which was left with after the suitable planets formed.
Vesta and Ceres should be for subjects of interest. These are two bodies evolved - objects are heated up and began to separate into different layers.
Surface detail"We think that Vesta has a metal core Center - a core of iron, and then surrounding silicate rock," explained Dr. Russell.
"And, then, at some point in its history, he beat her at the bottom and released a large amount of material." Part of this material gets bound in the Earth's atmosphere. One of every 20 viewed meteorites falling to the ground was identified with Vesta, "he added."
Ceres, which, 950 km in diameter, is by far the largest and most massive asteroid belt, body probably did not evolve much as Vesta.
Scientists believe likely he retains much water, perhaps in a band of deep ice below the surface.
Search for sunrise in Vesta in the coming months will be assigned the surface of the asteroid. The spacecraft carries instruments for detecting the elemental abundances and minerals in the rocks. It seeks evidence of geologic processes such as the mountain of construction and dislocation. The team is interested in understanding how Vesta surface has been remodeled by impacts and even over time lava flows.
Jonathan.Amos-Internet@BBC.co.UK
没有评论:
发表评论