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