Followed for 4 years now, the exoplanet Beta Pictoris b is one of the rare extra-solar worlds to be observed in direct imaging. A timelapse of his evolution around his star is even available.
Thousands of exoplanets are now in our cosmic address book (more than 3,700 in 2,818 planetary systems). But most were detected indirectly (via the transit method and the radial velocity method). Directly imaging these extra-solar worlds is a complicated undertaking, especially because of the high brightness of the parent stars. But a sufficiently large planet could be observed with a fairly powerful telescope. This is the case of Beta Pictoris b, followed for four years by the SPHERE instrument of ESO’s Very Large Telescope (VLT).
Discovered in 2008, Beta Pictoris b is a young exoplanet — about 23 million years old. It is also very massive — 13 times the mass of Jupiter — and very large: one and a half times the radius of Jupiter. It gravitates around its star at a distance of about 9 AU (nine times the Earth-Sun distance) and is located about 63 light years from Earth, in the Constellation Painter.
The direct imaging of exoplanets will be in the years to come our best chance to detect the possible presence of life elsewhere in the Universe — research conducted in our own system aside. The method could indeed make it possible to characterize the atmosphere of these worlds — if indeed there is one — revealing or not the presence of the ingredients necessary for life as we know it.
The video below shows a directly imaged planet
To do this, astronomers should be able to rely on new generation telescopes. We are thinking in particular of the GMagAO-X instrument, installed on the Giant Magellan Telescope (GMT), currently under construction at the Las Campanas Observatory (Chile), whose commissioning is scheduled for 2025. The highly anticipated James Webb Telescope (launch in 2021), 10 times more powerful than Hubble, should also be able to measure the atmospheric compositions of nearby exoplanets. We could then detect possible bio-signatures, and why not techno-signatures, confirming the existence of an extraterrestrial life, present or past.