The asteroid 1998 OR2 it is the largest space rock expected to pass close to Earth in April this year, and even amateurs will be able to see it in the sky.
A huge asteroid will make a brief visit to Earth in April and, although it is considered “potentially dangerous” for astronomers, the only show it will do in the coming centuries will be in the night sky.
Asteroid 1998 OR2 is believed to be up to 4.1 km in diameter, which would make it comparable to a decent-sized mountain in many parts of the world.
Fortunately, when he makes his next approach on April 29, he will pass a very safe distance of 6 million kilometers.
Still, it is considered potentially dangerous, because NASA’s Center for Near Earth Studies classifies anything reasonably bright that is about 7.4 million kilometers from Earth as such.
This means that there are many potentially dangerous asteroids out there that we know of and virtually none of them are a real risk to humans at any time.
But 1998 OR2 is still a big weapon – the largest asteroid that will fly close to our planet in 2020, in fact – which means it may be visible next month even for amateur astronomers.
NASA’s solar system ambassador, Eddie Irizarry, writes for the EarthSky:
Observers with telescopes at least 6 or 8 inches (the number indicates the size of the primary mirror) will see the asteroid (very slowly) moving in front of the stars.
Irizarry offers more detailed tips for detecting space rock on here.
If you don’t have a telescope large enough to make your own observation, the Virtual Telescope Project, based in Rome, will broadcast its ticket live, which will begin on April 28. VTP is already following the 1998 OR2 and took this image of him approaching:
And if you miss the date, this huge rock will fly even closer (but still totally safe) in 2079.
Other large space rocks will come close enough for observations in 2024 and 2027.
In 2029, the mega-asteroid Apophis (which is actually slightly smaller than 1998 OR2) will make a passage that has already been a cause for concern. Since then, it has been determined that Apophis poses no threat, so enjoy the night sky watching fearlessly for at least another decade, unless something happens to us, as it sometimes does.