SPACE TELESCOPES FIND FIRST EXOMOON
Astronomers using Hubble and Kepler space telescopes found compelling proof for existence of the first known moon outside the solar system
8,000 light-years away, the exo moon is orbiting a gasgiant planet
The finding was published in the journal Science Advances
284 Kepler-discovered planets were analysed by researchers when looking for exomoons
Exomoons had wide orbits, revolving over 30 days, around their host star
Observations measured momentary dimming of starlight as a planet passed in front of its star, called a transit.
The researchers found Kepler 1625b had intriguing anomalies
The planet before and during its 19hour-long transit across the face of the star monitored by the researchers.
After it ended, Hubble detected a second and much smaller decrease in the star’s brightness 3.5 hours later
It was consistent with a moon trailing the planet like a dog following its owner on a leash
In addition to this dip in light, Hubble provided supporting evidence for the moon hypothesis
It measured that the planet began its transit 1.25 hours earlier than predicted
An exomoon — moons orbiting planets in other star systems — is unusual because of its large size, comparable to Neptune
IF CONFIRMED BY HUBBLE OBSERVATIONS, THE FINDING OF EXOMOONS COULD PROVIDE VITAL CLUES ABOUT THE DEVELOPMENT OF PLANETARY SYSTEMS AND MAY CAUSE EXPERTS TO REVISIT THEORIES OF HOW MOONS FORM AROUND PLANETS — DAVID KIPPING, Assistant professor of astronomy, Columbia University