An object orbiting the earth that some observers speculated could have alien origins is in fact a natural rock, according to a new report.
The asteroid, designated 1991 VG, is approximately 20 meters in diameter and was first observed orbiting close to Earth in 1991, according to Cosmos Magazine.
The asteroid immediately attracted attention when it was discovered by astronomer James Scotti in November 1991. It had a heliocentric orbit very similar to Earth's and it had unusual fluctuations in brightness and speed for its size.
It disappeared from Earth's orbit in 1992, but astronomers predicted it would return in 2017.
In 1995, astronomer Duncan Steel wrote a paper in which he raised the possibility that 1991 VG was an alien object, but ultimately dismissed the suggestion.
"I do not think [VG 1991] is of extraterrestrial origin," Steel told Vice in 2015. "I do think that we should take seriously the possibility that there are alien artifacts in the solar system, although I very much doubt that there are any, based on what we know so far."
Nonetheless, Steel's paper fueled speculation that 1991 VG was of alien origin. The debate grew as 2017, and the return of 1991 VG, approached.
Carlos and Raul de la Fuente Marcos, two astronomers from Madrid University in Spain, examined the questions surrounding 1991 VG by using current asteroid science, which has advanced considerably since 1991.
The two scientists wrote that 1991 VG "was briefly captured by Earth's gravity as a mini-moon during its previous fly-by in 1991-1992," according to Cosmos.
They went on to note that the asteroid "is not a present-day co-orbital companion of the Earth."
In addition, they pointed out that 1991 VG is not unique. Similar asteroids have been observed from Earth, including objects spotted in 2001, 2008 and 2014. None of those objects triggered theories about potential alien origin.
"All this evidence confirms that there is no compelling reason to believe that 1991 VG is not natural," concluded the authors.
Even if the issue with 1991 VG appears settled, other questions still remain.
"My question is where did 1991 VG come from and how did it get into its present orbit?" Scotti stated in an email to Vice. "One possibility would be that it is ejecta from a lunar impact. Another possibility is that the Yarkovsky force, caused by the thermal emissions of a rotating object, systematically pushed the object around over long times. It's still a puzzle!"