A mysterious object has been spotted by NASA hurtling through space at about 1.6 million km/h (1 million miles per hour). The object is moving at such a velocity that it could exit the Milky Way entirely, and scientists are trying to establish what it is. The object, known as CWISE J1249, is currently 400 light years from Earth, the object and is very unlikely to be a probe due to its large size.

NASA citizen scientists notice an object moving 1 million mph

Around 30,000 times larger than Earth, CWISE J1249 is 8 percent of the Sun’s mass. Due to its unusual size, it is considered to be somewhere between a star and a planet, according to Dr Darren Baskill, astronomy lecturer at the University of Sussex.

Using data from NASA’s WISE telescope, which later became the NEOWISE mission, a faint, fast-moving object was noticed zooming out of the Milky Way. While most familiar stars generally peacefully orbit in the center of the Milky Way, citizen scientists working on NASA’s Backyard Worlds: Planet 9 project have helped discover an object that is moving so fast that it will escape the Milky Way’s gravity and shoot into intergalactic space. This hypervelocity object is the first such object discovered with the mass of a small star.

Using images from NASA’s WISE or Wide Field Infrared Explorer mission, Backyard Worlds mapped the sky in infrared light from 2009 to 2011. It was reactivated as NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer) in 2013 and retired on August 8, 2024.

In recent history, longtime Backyard Worlds citizen scientists Martin Kabatnik, Thomas P. Bickle and Dan Caselden spotted a faint, fast-moving object dubbed CWISE J124909.08+32116.0 zooming across their screens in the WISE images. Their follow-up observations with several ground-based telescopes enabled scientists to confirm the discovery and to characterize the object. In a journal, Astrophysical Journal Letters, the citizen scientists have co-authored the team’s study about their discovery.

According to Kabatnik, a citizen scientist from Nuremberg, Germany, when they first noticed how fast the object was moving, they were convinced that it must have been reported already.

CWISE J1249 is hurtling out of the Milky Way at roughly 1 million miles per hour. However, it is also noticeable due to its low mass, which makes it difficult to classify as a celestial object. It could potentially be a low-mass star, or if it doesn’t steadily fuse hydrogen in its core, it could be considered a brown dwarf, which places it somewhere between a gas giant planet and a star.

The unusual nature of rapidly moving stars

According to Dr Darren Baskill, astronomy lecturer at the University of Sussex:

“Such rapidly moving stars are unusual. Locally, only one or two stars out of every thousand are moving at such a speed, and a star moving as rapidly as J1249 would be leaving our Milky Way galaxy in just a few tens of millions of years: a blink of an eye for such stars that can live for tens of billions of years.

“To put the speed of J1249 into perspective, it is moving 2.6 times faster than the fastest space probe ever launched, which is the speed that the Parker space probe reached when it looped around the Sun in June 2024,” Baskill explained.

So why do researchers think that it is moving so fast?

Although the gigantic object is only moving at 0.001 per cent of the speed of light, it could break free from our galaxy and soar off into intergalactic space. The strange object could be the remnants of a binary system gone wrong: its companion, a white dwarf, might have exploded in a supernova after pulling off too much material from J1249. Alternatively, scientists think it may have come from a cluster of stars that were rapidly dispersed after encountering a pair of black holes.