This year has been an extremely active year for news of asteroids and comets with NASA's OSIRIS-REX touching down on asteroid Bennu last month, and a veritable flurry of comets whizzing past our Big Blue Marble like F3 Neowise, F8 Swan, P1 Neowise, M3 Atlas, and S3 Erasmus arriving in the sky this fall.
Now a team of astronomers at The University of Hawai’i is warning that there is a slim chance an asteroid named after Apophis, the Egyptian God of Chaos, might make close contact with Earth 48 years from now in the year 2068. Recent observations have seen slight alterations in the looming asteroid's orbit, and although the cause for concern is firmly on scientists' minds, the actual odds of a collision are still very remote.
““We have known for some time that an impact with Earth is not possible during the 2029 close approach. The new observations we obtained with the Subaru telescope earlier this year were good enough to reveal the Yarkovsky acceleration of Apophis," explained astronomer Dave Tholen, of the University of Hawaii.
"They show that the asteroid is drifting away from a purely gravitational orbit by about 170 meters per year, which is enough to keep the 2068 impact scenario in play.”
Tholen and his team first discovered Apophis back in 2004 and the hurtling space rock is actually slated to first whoosh past Earth in 2029 in a completely harmless transit with zero opportunity for anything dramatic. Upon its closest approach on April 13, 2029, Apophis will zoom so near to Earth that the 1,000-foot-wide body will cruise between our world and its outer web of communication satellites, and may even be visible using our unaided eyes.
Tholen and his team's findings were offered up at a 2020 meeting of the American Astronomical Society, where they revealed that they have been carefully tracking and monitoring the shifting orbit of Apophis since 2004.
In an orbital process called the Yarkovsky effect, astronomers have found that Apophis has increased its speed slightly.
This gentle boost is caused by asteroid surfaces heating up during the day and cooling down at night, casting off radiation as heat that performs as a mini-thruster and causing rotating asteroids to sometimes wander widely in their orbits. This obviously makes it difficult for scientists to accurately predict long-term risks to our planet.
International space agencies are continually monitoring heavenly objects that might pose a threat, something that is essential when dealing with an asteroid with characteristics of Apophis which has a minuscule-but-real chance of inflicting damage.
To help combat future asteroid intruders and in a perfectly timed operation, NASA and SpaceX are launching the DART mission in 2021, which will act as a practice drill in which small spacecraft might be used to batter and deflect dangerous rogue space rocks from Earth.