The "lost planet" made its second appearance, 3 years later, in a discovery that could help us explore extraterrestrial life.
The planet is believed to be among hundreds of worlds that have "vanished," and now may be rediscovered, using new techniques.
NGTS -11b , as the planet is known, first appeared in 2018 in NASA's TESS telescope, and is one of many exoplanets discovered by the space agency 's TESS telescope . Like all worlds discovered by this technology, it was detected when it passed in front of its star, causing a burst of light that could be seen from Earth. Of course, it has never been seen again since, and without the opportunity for a second look, the planet was simply "lost."
Now, researchers hope they can detect these lost worlds, and by extension find cooler planets closer to our own solar system. Some of these planets could be habitable, scientists hope.
NGTS-11b is 620 light-years away and orbits its star five times closer than Earth to the Sun. It has the mass and size of Saturn, and its orbit takes 35 days. Note that although it is very close to its star, and many would expect it to be warm enough to support life, it is closer to the "Goldilocks zone," so the lost planet is not too hot or cold compared to other planets.
One reason for its disappearance was that the TESS telescope scans most of the sky every 27 days, and so it can often appear to pass its star only once. Before it reappears, the telescope is surveying another part of the sky, leaving astronomers unable to conduct further research.
The new research sees scientists from the University of Warwick examining the findings the lost planet may hold, using a different telescope, the Next-Generation Transit Survey (NGTS) in Chile. With this technology, they were able to observe the star for 79 nights, and were able to see this world for the second time.
"In chasing this second transit, we found a planet of a longer period. It is the first, I hope, of many such finds, and planets of a more distant period," said Samuel Gill of Warwick.
«These discoveries are rare but significant, as they allow us to find planets with longer periods than those found by other astronomers. Planets with longer periods are cooler, more like the planets of our own solar system.»
«The lost planet, NGTS-11b, has a temperature of just 160°C, which means it is cooler than Mercury and Venus. Of course, while this temperature is too high to support life as we know it, it is closer to the Goldilocks zone than other previously discovered planets, which typically have temperatures above 1,000°C..»
The lost planet paved the way for scientists, and now they hope to use the same technique to find many more like the lost planet, and get closer to identifying other worlds that could be habitable or even already inhabited.
«"There are hundreds of individual transits detected by TESS, and we will monitor them using this method," said Dr. Gill. "This will allow us to discover cooler exoplanets of all sizes, including planets that are more like those in our own solar system. Some of these will be small rocky planets in the Goldilocks zone, cool enough to host liquid oceans and possibly alien life.".»
