OSIRIS-REx is about to fling samples of the asteroid Bennu at Earth

Bits of the asteroid Bennu are coming again to Earth. NASA’s OSIRIS-REx spacecraft took samples of the asteroid in 2020 that are scheduled to reach on Earth on 24 September.

OSIRIS-REx launched in 2016 and entered orbit round Bennu in 2018. Scientists selected Bennu as a goal primarily due to its comparatively small distance from Earth – on the time of launch, it was about 225 million kilometres away, and within the intervening years it obtained as shut as 50 million kilometres from Earth.

Due to its common shut approaches, Bennu is taken into account a near-Earth object (NEO). It’s not anticipated to smash into our planet anytime quickly, however there’s a couple of 0.057 per cent likelihood of a collision within the subsequent 300 years. Bennu is about 490 metres throughout, so if it did crash into Earth it could trigger important harm.

One cause to check Bennu is to determine find out how to defend Earth from it and comparable asteroids. However one other is that it is without doubt one of the most primitive house rocks we all know of. “Asteroids like Bennu are time capsules from the early photo voltaic system, particles that’s left over from the formation of the photo voltaic system,” says Anjani Polit on the College of Arizona, a part of the OSIRIS-REx crew.

Such asteroids in all probability clustered collectively to kind our photo voltaic system’s planets, so we will use them to know how the planets fashioned and grew. Bennu particularly hosts giant concentrations of carbon, the principle constructing block of natural molecules – which in flip are the constructing blocks for all times as we all know it.

“We’re fairly certain that there will probably be natural molecules in these samples,” says OSIRIS-REx scientist Michelle Thompson at Purdue College in Indiana. “Finding out these natural molecules would possibly assist us perceive what organics had been round within the early photo voltaic system that would have seeded life on Earth.”

Related samples have already been returned by Japan’s Hayabusa2 spacecraft, which visited an asteroid referred to as Ryugu. A key element of the researchers’ aim of understanding the historical past of the photo voltaic system will probably be evaluating mud samples from these two objects.

“Let’s say you’re a customer to Earth and also you need to be taught all about Earth’s geologic historical past, so that you choose up one rock – you’re by no means going to have the ability to be taught that,” says Thompson. “Going to a couple of completely different asteroid actually opens up an entire new world to actually perceive the range of fabric that was round 4.5 billion years in the past”, in regards to the time when the photo voltaic system fashioned.

On 24 September, the day will begin early for the OSIRIS-REx crew. Within the wee hours of the morning, the crew’s engineers will make a name about whether or not it’s secure to launch the pattern capsule. If they provide the “go”, it will likely be despatched hurtling in the direction of Earth from about 102,000 kilometres away, greater than 1 / 4 of the gap to the moon. It would journey for about 4 hours earlier than slamming into the environment at round 44,000 kilometres per hour. Throughout its descent, it will likely be protected and slowed by a warmth defend and two parachutes till it touches down within the Utah desert.

“As soon as we launch the capsule, there’s nothing else we will do besides wait and hope the whole lot goes easily,” says Polit. “All these years of labor, all of it comes right down to that 13-minute descent by means of the environment.” If the capsule can’t be launched on 24 September, it will likely be two years earlier than researchers have an opportunity to strive once more.

If it may be launched, although, the OSIRIS-REx spacecraft will proceed on in the direction of an prolonged mission on the asteroid Apophis. On Earth, the pattern it drops will probably be instantly scooped up and despatched to Houston for scientists to analyse. “I actually really feel like a child on Christmas Eve,” says Thompson. “I’m about to get up and get all these presents of samples from Bennu.”