Context:

• After a two-year chase, a NASA spacecraft arrived on December 3 at the ancient asteroid Bennu, its first visitor in billions of years.

Importance of this mission:

• The carbon-rich asteroid Bennu could hold evidence dating back to the beginning of our solar system 4.5 billion years ago.
• As such, it is an astronomical time capsule.
• NASA has brought back comet dust and solar wind particles before, but never asteroid samples.

About Osiris-Rex

• The $800 million Osiris-Rex mission began with a 2016 launch from Cape Canaveral, Florida.
• Both the spacecraft and asteroid’s names come from Egyptian mythology. Osiris is the god of the afterlife, while Bennu represents the heron and creation.
• Osiris-Rex is actually a NASA acronym for origins, spectral interpretation, resource identification, security-regolith explorer.
• Osiris-Rex aims to collect at least 60g of dust and gravel.
• The spacecraft won’t land, but rather use a 10-foot (3-metre) mechanical arm in 2020 to momentarily touchdown and vacuum up particles.
• The sample container would break loose and head toward Earth in 2021.
• The collection parachuting down to Utah would represent the biggest cosmic haul since the Apollo astronauts hand-delivered moon rocks to Earth in the late 1960s and early 1970s.

Japan’s second asteroid mission

• A Japanese spacecraft, meanwhile, has been hanging out at another near-Earth asteroid since June, also for samples.
• It is Japan’s second asteroid mission. This latest rock is named Ryugu and about double the size of Bennu.
• Japan has also managed to return some tiny particles in 2010 from its first asteroid mission, also named Hayab

Potentially hazardous asteroids

• Both Bennu and Ryugu are considered potentially hazardous asteroids.
• That means they could smack Earth years from now. At worst, Bennu would carve out a crater during a projected close call 150 years from now.
• Contact with Bennu will not significantly change its orbit or make it more dangerous to us.

Source:TH