December 3, 2018, marks the date when NASA’s OSIRIS-REx probe will commence the final stage of its journey towards Bennu, a potentially hazardous space rock, 500 meters wide.
NASA’s probe will touch down on the space rock, collect a sample, and return it back to Earth for scientists to study.
Astronomers have suggested that Bennu may be packed with the building blocks of life, which means that recovering samples from its surface will allow scientists on Earth to understand asteroid better, and test a number of theories which argue that asteroids can transport vital chemicals to planets, helping life come into existence.
It now takes nearly 14 minutes round-trip for me to communicate with my team back on Earth. 🛰 ↔️ 📡 My light time will increase as I approach #asteroid Bennu and will be more than 20 minutes during sample collection.
— NASA's OSIRIS-REx (@OSIRISREx) November 26, 2018
And while steroids such as Bennu may be transporters of life, such space rocks represent a great danger for Earth. Through samples collected by NASA’s OSIRIS-REx probe, scientists will better understand the threat such object represent to Earth.
That feeling when you’re only one day away from a destination you’ve been dreaming about for your whole existence: 🤩
— NASA's OSIRIS-REx (@OSIRISREx) December 2, 2018
If an object such as Bennu were to impact Earth, it would release more energy than all nuclear weapons detonated in the entirety of human history. In fact, scientists have calculated that the impact of an asteroid similar to Bennu would be equivalent to 1,200 megatons. This is 80,000 times the energy released by the Hiroshima bomb.
And while such an impact would create an apocalyptic scenario, it would not wipe out all life on Earth.
On one of the busiest travel days of the year, here's an update from my journey … I'm covering about 4.4 miles per day and my destination — Bennu — looks like this from 85 miles away. ➡️ https://t.co/kpaWjAu2Ri pic.twitter.com/I14ucDtf9l
— NASA's OSIRIS-REx (@OSIRISREx) November 23, 2018
Bennu truly is a behemoth. The space rock is as wide as five football fields and has a total weight of around 79 billion kilograms.
Astronomers have calculated a 1 in 2,700-chance of Bennu impacting Earth between 2175 and 2199. Mathematically those chances are really small, so there is no need to stack up on toilet paper just yet.
“We’re not talking about an asteroid that could destroy the Earth,” Nasa Osiris-Rex principal investigator Dante Lauretta explained in 2016.
“We’re not anywhere near that kind of energy for an impact.”