If you look up at the sky on April 13, 2029, you’ll see a streak of light that looks like cinematic special effects, except this won’t be a sci-fi movie.
What that blaze in the cosmos really will be is the asteroid 99942 Apophis. You could almost legit call it a shooting star, since it’s expected to shine as bright as some of the stars that twinkle in the Little Dipper and to zoom across the full moon. This thing will also be a shocking 19,000 miles above the surface. That is as close as some of the spacecraft orbiting our planet, except a 340-meter-wide space rock is going to make people nervous. It even made NASA nervous. And thrilled.
“Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs),” said Paul Chodas, director of NASA JPL’s Center for Near Earth Objects Studies (CNEOS). “By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense.”
NASA started buzzing about this asteroid in 2004, when two separate teams of astronomers observed Apophis, which was later determined to have a 2.7 percent chance of pulling a Deep Impact ten years from now (that was a comet, but still, same result if it crashed into Earth). That doesn't sound like much, but it is alarming to astronomers. Later observations of the object’s orbit showed that there was no chance of it actually making a disaster film come true.
It obviously doesn't end there. Apophis has been stalked by telescopes ever since, so NASA and international space agencies have an idea of where exactly it’s headed in the future. While its trajectory doesn't suggest any danger, there still is a 1 in 100,000 chance of impact decades after the initial flyby. Even that is far from impending doom.
Apophis will give scientists a rare opportunity to observe an asteroid in action. Questions that are being discussed at the 2019 Planetary Defense Conference going on right now include how Earth’s gravity will affect the asteroid’s orbit, what to do in case it ventures too close, and whether we can learn more about the innards of an asteroid from this event. A spacecraft mission that will close enough to beam back valuable information is also being considered. Whether the spacecraft will survive, nobody knows.
“We already know that the close encounter with Earth will change Apophis’ orbit, but our models also show the close approach could change the way this asteroid spins, and it is possible that there will be some surface changes, like small avalanches,” said CNEOS astronomer David Farnocchia.
So don’t start doomsday prepping just yet, but the thought of a cosmic event that could pass for SFX still is pretty cool.