According to NASA astronomers, the 5,000-plus exoplanets confirmed so far include small, rocky worlds like Earth, gas giants many times larger than Jupiter, and ‘hot Jupiters’ in scorchingly close orbits around their parent stars.
Our Milky Way Galaxy likely holds hundreds of billions of exoplanets.
The steady drumbeat of discovery began in 1992 with strange new worlds orbiting an even stranger star.
It was a type of neutron star known as a pulsar, a rapidly spinning stellar corpse that pulses with millisecond bursts of searing radiation.
Measuring slight changes in the timing of the pulses allowed scientists to reveal planets in orbit around the pulsar.
“Finding just three planets around this spinning star essentially opened the floodgates,” said Pennsylvania State University’s Professor Alexander Wolszczan, lead author on a paper that unveiled the first exoplanets.
“If you can find planets around a neutron star, planets have to be basically everywhere. The planet production process has to be very robust.”
A new raft of discoveries marks a scientific high point — more than 5,000 confirmed exoplanets.
The planetary odometer turned on March 21, 2022, with the latest batch of 65 planets added to NASA’s Exoplanet Archive.
“We’re opening an era of discovery that will go beyond simply adding new planets to the list,” Professor Wolszczan said.
“It’s not just a number. Each one of them is a new world, a brand-new planet. I get excited about every one because we don’t know anything about them,” added Dr. Jessie Christiansen, science lead for NASA’s Exoplanet Archive and a researcher with NASA’s Exoplanet Science Institute at Caltech.
NASA’s Transiting Exoplanet Survey Satellite (TESS), launched in 2018, continues to make new exoplanet discoveries.
But soon powerful next-generation telescopes and their highly sensitive instruments, starting with the recently launched NASA/ESA/CSA James Webb Space Telescope, will capture light from the atmospheres of exoplanets, reading which gases are present to potentially identify tell-tale signs of habitable conditions.
The Nancy Grace Roman Space Telescope, expected to launch in 2027, will make new exoplanet discoveries using a variety of methods.
ESA’s ARIEL mission, launching in 2029, will observe exoplanet atmospheres.
“To my thinking, it is inevitable that we’ll find some kind of life somewhere — most likely of some primitive kind,” Professor Wolszczan said.
“The close connection between the chemistry of life on Earth and chemistry found throughout the Universe, as well as the detection of widespread organic molecules, suggests detection of life itself is only a matter of time.”
“The launch of NASA’s now-retired Kepler Space Telescope in 2009 opened a new window on the Universe,” said Kepler principal investigator Dr. William Borucki.
“I get a real feeling of satisfaction, and really of awe at what’s out there.”
“None of us expected this enormous variety of planetary systems and stars. It’s just amazing.”
This article is based on text provided by the National Aeronautics and Space Administration.
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