There’s no need to worry about Planet X destroying Earth in October … we may not make it past February. NASA has spotted not one but two big space objects heading towards Earth, with one coming close enough to see with binoculars. Is that close enough to be afraid?
(This comet) has a good chance of becoming visible through a good pair of binoculars, although we can't be sure because a comet's brightness is notoriously unpredictable.
That not-too-comforting comment comes from Paul Chodas, manager of NASA's Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California. The NEO he’s describing is comet C/2016 U1, which was discovered by the NEOWISE asteroid-hunting project in October 2016 and is in the southeastern sky over the northern hemisphere just before dawn this week – nothing like a little advanced warning, NASA! While it looks big and close, C/2016 U1 doesn’t get any closer than 66 million miles (106 million km) from Earth before it swings around the Sun inside the orbit of Mercury and heads back out into space for another few thousands years. Maybe by the time it gets back, NASA will have the technology to figure out how big it actually is.
Assuming we survive C/2016 U1, we have about six weeks to get ready for the more ominous 2016 WF9. Discovered by NEOWISE on November 27, 2016, this space ball is big and spooky. It measures 0.3 to 0.6 miles (0.5 to 1 km) in diameter and is made up of a dark matter (not THAT dark matter) that reflects very little light. This dark surface has NASA researchers arguing over whether 2016 WF9 is a comet or an asteroid. While its orbit says “comet,” its lack of a dust and gas cloud says “asteroid.”
Meanwhile, Earth says “Who cares what it is … when is it coming and how close is it going to get?” Estimated date of arrival for 2016 WF9 is February 25, 2017, when it will enter inside Earth’s orbit at a distance of nearly 32 million miles (51 million km) away. While that’s much closer than C/2016 U1, its dark surface means it can’t be seen with binoculars. That distance also means it’s not putting the planet in any danger … for now.
However, it’s close enough that astronomers may be able to solve the mystery of whether it’s a comet or an asteroid … or something else, according to Deputy Principal Investigator James Bauer at JPL.
2016 WF9 could have cometary origins. This object illustrates that the boundary between asteroids and comets is a blurry one; perhaps over time this object has lost the majority of the volatiles that linger on or just under its surface.
Two more space balls - one bright, one big, dark and mysterious - pass close by Earth. Is a few weeks notice enough of a warning?