December 12, 2024

Look Up and Watch a 1.1-km Asteroid Fly Past Earth Today – Here’s How

The asteroid was found on the night of August 9th, 1994 by astronomer Robert McNaught observing from the Siding Spring Observatory. The Apollo asteroid is an Earth-crosser, with a perihelion interior to our own at 0.9 Astronomical Units (AU) from the Sun, and an aphelion out in the asteroid belt at 1.8 AU, with an orbital period of 572 days.
The orbit of asteroid 1994 PC1. Credit: NASA/JPL
Enjoyable truth: looking back through sky plates, 1994 PC1 in fact turns up in images all the way back to 1974.
1994 PC1 is a S-class stony-type asteroid, and is just somewhat bigger than another widely known NEO asteroid 101955 Bennu the target of NASAs Osiris-Rex sample return objective, which goes back to Earth with its precious cargo late next year.
This weeks pass is the closest for the asteroid since January 17, 1933 (pre-discovery) at 0.00752 AU, and the closest for the next two centuries, although the pass on January 18, 2105 is nearly as close, at 0.01556 AU.
A closeup of Tuedays flyby. Credit: NASA/JPL
Hunting the Asteroid
This weeks close method provides observers an opportunity to see the asteroid for themselves. Thats fast enough to see the motion of the quick asteroid versus the starry background after enjoying it at the eyepiece for just a minute or two.
I keep in mind the excitement of seeing asteroid 4179 Toutatis on its close pass in 2004. That passage was extremely similar to this weeks, seeing as the space rock calmly crept throughout the stellar background.
The good news is, you might have started searching for 1994 PC1 last night: the asteroid is still a respectable +12 th magnitude plus on either eve or after closest method, January 17th or January 19th. Unlike closer passes, parallax versus observer location wont play too much of an element in the asteroids real position in the sky.
To capture it, youll require a telescope capable of precisely pointing at coordinates in right ascension and declination. You can get these ephemerides for your time and area by inputting 1994 PC1 at NASA/JPL Horizons site.
The path of the asteroid for the last 12 hours of January 17th. Credit: Starry Night
The night of Monday, January 17th finds asteroid 1994 PC1 low to the south at sunset on the border of the southern hemisphere constellations of Fornax and Eridanus. Difficult, though not an impossible target for North American observers.
The 24 hour course of asteroid 1994 PC1 for January 18th, in one hour increments. Credit: Starry Night
The essential night of Tuesday, January 18th sees the asteroid making its closest pass by Earth for this century. Standing on the surface area of the asteroid Tuesday night, you d see the Earth as a 22 half-full disk, slightly smaller sized than a Full Moon.
A close up of the pass near Alrescha (Alpha Piscium) from 21:02 to 21:29 UT. Credit: Starry Night
Wednesday night January 19th sees the asteroid much further north in the constellation Andromeda. Though now nearly 1.7 million miles far-off, Wednesday also has the benefit of using a slim window for viewing after golden ends, and before the waning gibbous Moon rises.
The celestial path of asteroid 1994 PC1 through Wednesday, January 19th. Credit: Starry Night.
Clouded out? Astronomer Gianluca Masi and the Virtual Telescope Project has you covered, with a live webcast following 1994 PC1 beginning at 20:00 UT on the 18th.
Fortunately, asteroid 1994 PC1 wont use us the same doomday situation as the current funny Look Up … just a great program. All the best and clear skies on your mission to find asteroid 1994 PC1.
Originally published on Universe Today.

We have such a possibility coming right up on the night of Tuesday, January 18th, when 1.1-kilometer asteroid (7482) 1994 PC1 passes 1.23 million miles (1.98 million kilometers) from the Earth. The asteroid was found on the night of August 9th, 1994 by astronomer Robert McNaught observing from the Siding Spring Observatory. The Apollo asteroid is an Earth-crosser, with a perihelion interior to our own at 0.9 Astronomical Units (AU) from the Sun, and an aphelion out in the asteroid belt at 1.8 AU, with an orbital period of 572 days. The key night of Tuesday, January 18th sees the asteroid making its closest pass by Earth for this century. Standing on the surface of the asteroid Tuesday night, you d see the Earth as a 22 half-full disk, slightly smaller than a Full Moon.

This weeks phantom of asteroid 1994 PC1 uses observers a chance to see an area rock relocating actual time.
In a slow moving universe, asteroids offer us an uncommon opportunity to see things relocating actual time. We have such a possibility coming right up on the evening of Tuesday, January 18th, when 1.1-kilometer asteroid (7482) 1994 PC1 passes 1.23 million miles (1.98 million kilometers) from the Earth. This is about five times the distance from the Earth to the Moon, and just a shade over the range to the anti-sunward Earth-Sun Lagrange 2 point, soon to be the house of the James Webb Space Telescope.