I want to begin this month’s column with a brain teaser: What did OSIRIS-REx say after orbiting Bennu for a couple of years? Before you answer, you may need a little background.
OSIRIS-REx is a spacecraft that was launched by NASA in 2016 and has been in orbit around the asteroid Bennu since 2018, where it will remain until 2023. The actual name represented by the spacecraft’s initials is too long for this column, but it is basically a sample return mission. OSIRIS-REx has been studying the asteroid for two years and recently touched down briefly to collect some asteroid stuff before returning to orbit. It will remain in orbit around Bennu until 2023 at which time it will bring its asteroid sample back to Earth for us to study and enjoy.
This is not the first mission to bring stuff from space back to Earth, but it will be returning with the biggest and best sample to date. And the method used to collect the sample is imagination at its finest. At 200 million miles distant, the spacecraft is too far for real time commands so the entire orbit, descent, and collection sequence had to be pre-programmed. The meticulous planning for the sample collection was impressive and included orbiting the asteroid for two years while mapping and studying potential sites. The spacecraft then touched down for about five seconds, allowing the sampling arm to release a burst of nitrogen gas which stirred up rocks and soil that were captured in the sampler head. The collection was a great success and can be watched on YouTube. So the answer to the brain teaser mentioned earlier is, “Tag, you’re it.”
So what’s the big deal about asteroid dirt that would motivate NASA to devote many years and resources to the mission? First and foremost, asteroids are believed to be leftover remnants of the formation of the solar system that, unlike planets and meteorites, have remained unchanged over the past several billion years.
As was explained to me by Dr. Harold Reitsema, co-investigator on numerous NASA missions, the fact that the collected sample is not only large (ounces, not particles) but also pristine, unchanged, and unaffected by geological forces since the formation of the solar system.
Second, they are relatively close and easy to get to. Third, there are lots of them so we have many targets from which to choose. Asteroids have also been the center of speculation regarding the possibility of mining them for useful minerals.
This month also has some real time observing opportunities involving all the naked-eye planets. During your morning commute you have probably already noticed Venus as a bright beacon in the eastern sky. It will be joined by much fainter Mercury as the month progresses.
After sunset, Jupiter and Saturn continue the show they have been performing for the past several months, drawing closer and closer low in the southwest as the days progress. Mars is also visible in the evening, though much fainter, high in the south near the Great Square of Pegasus.
I strongly encourage readers to take a look at Jupiter and Saturn at every opportunity this month and next, because in December the two will appear closer to each other than they have since 1623. Like me, you probably missed that one so you won’t want to miss this one, easily visible next month helping you enjoy what’s up in the sky.
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NASA, Asteroid, OSIRIS-REx, Spacecraft, 101955 Bennu, Earth
World news – US – What’s Up in the Sky: Spacecraft in the news and planets in the sky