This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.bbc.co.uk/go/rss/int/news/-/news/science-environment-14160135
The article has changed 7 times. There is an RSS feed of changes available.
| Version 0 | Version 1 |
|---|---|
| Dawn probe set to orbit Asteroid Vesta | Dawn probe set to orbit Asteroid Vesta |
| (40 minutes later) | |
| By Jonathan Amos Science correspondent, BBC News | By Jonathan Amos Science correspondent, BBC News |
| The US space agency says its Dawn probe should go into orbit around the Asteroid Vesta early on Saturday (GMT). | |
| The robotic satellite will be spending a year at the 530km-wide body before moving on to the "dwarf planet" Ceres. | |
| New pictures on Dawn's approach to Vesta show the giant rock in unprecedented detail. | New pictures on Dawn's approach to Vesta show the giant rock in unprecedented detail. |
| The asteroid looks like a punctured football, the result of a colossal collision sometime in its past that knocked off its south polar region. | The asteroid looks like a punctured football, the result of a colossal collision sometime in its past that knocked off its south polar region. |
| Dawn's encounter is occurring about 188 million km (117 million miles) from Earth. Engineers have put the spacecraft on a course to be captured in the gravitational field of Vesta. | Dawn's encounter is occurring about 188 million km (117 million miles) from Earth. Engineers have put the spacecraft on a course to be captured in the gravitational field of Vesta. |
| They expect to hear confirmation from the satellite on Saturday that it is safely circling the rock. | They expect to hear confirmation from the satellite on Saturday that it is safely circling the rock. |
| Initially, Dawn will be about 16,000km (9,900 miles) from the asteroid, but this distance will be reduced over time. | Initially, Dawn will be about 16,000km (9,900 miles) from the asteroid, but this distance will be reduced over time. |
| "It has taken nearly four years to get to this point," said Robert Mase, Dawn project manager at Nasa's Jet Propulsion Laboratory in Pasadena, California. "Our latest tests and check-outs show that Dawn is right on target and performing normally." | "It has taken nearly four years to get to this point," said Robert Mase, Dawn project manager at Nasa's Jet Propulsion Laboratory in Pasadena, California. "Our latest tests and check-outs show that Dawn is right on target and performing normally." |
| Scientists believe asteroids can help them understand more about the earliest days of the Solar System. These wandering rocks are often described as the rubble that was left over after the planets proper had formed. | Scientists believe asteroids can help them understand more about the earliest days of the Solar System. These wandering rocks are often described as the rubble that was left over after the planets proper had formed. |
| Vesta and Ceres should make for interesting subjects. They are both evolved bodies - objects that have heated up and started to separate into distinct layers. | Vesta and Ceres should make for interesting subjects. They are both evolved bodies - objects that have heated up and started to separate into distinct layers. |
| In the case of Vesta this probably means it has an iron core. | In the case of Vesta this probably means it has an iron core. |
| Ceres, which, at 950km in diameter, is by far the largest and most massive body in the asteroid belt, may not have got that far. | Ceres, which, at 950km in diameter, is by far the largest and most massive body in the asteroid belt, may not have got that far. |
| Scientists think it probably retains a lot of water, perhaps in a band of ice deep below the surface. | Scientists think it probably retains a lot of water, perhaps in a band of ice deep below the surface. |
| Jonathan.Amos-INTERNET@bbc.co.uk | Jonathan.Amos-INTERNET@bbc.co.uk |