Nasa’s planet-hunting TESS spacecraft that will map 85 per cent of the sky in search of alien worlds is launching today.
The planet-hunting spacecraft is due to lift off at 11.51pm BST (6.51pm ET) from Cape Canaveral in Florida.
It will travel to nearby stars in our galaxy to find unknown exoplanets that are outside our solar system.
It is hoped that by understanding the stars and their planets better, we might one day be able to tease out signs of alien life.
This image made available by NASA shows an illustration of the Transiting Exoplanet Survey Satellite (TESS). The spacecraft will prowl for planets around the closest, brightest stars. These newfound worlds eventually will become prime targets for alien life
The washing-machine-sized spacecraft – which is flying on a SpaceX Falcon 9 rocket – was initially set to launch on Monday at 11:32 pm BST (6:32 pm ET).
However, it was delayed to allow additional time for Guidance and Control Analysis and will set off this evening instead.
‘Launch teams are standing down today to conduct additional Guidance Navigation and Control analysis,’ NASA tweeted on Monday afternoon.
‘The NASA TESS spacecraft is in excellent health and remains ready for launch on the new targeted date of Wednesday, April 18.’
The live stream can be accessed on the SpaceX website or Nasa’s TV starting at 11.30pm BST (7.30pm ET).
Tess – The Transiting Exoplanet Survey Satellite – is set to embark on a two-year quest to find and identify mystery worlds thought to be lurking in our cosmic backyard.
The spacecraft aims to add thousands of exoplanets, or planets beyond our solar system, to the galactic map for future study.
Life might be out there, whether microbial or more advanced, and scientists say Tess and later missions will help answer the age-old question of whether we’re alone.
Tess (pictured) is designed as a follow-on to the US space agency’s Kepler spacecraft, which was the first of its kind and launched in 2009
‘It is very exciting. … By human nature, we look for exploration and adventure, and this is an opportunity to see what’s next,’ NASA’s Sandra Connelly, a science program director, said last week.
The $337 million (£236 million) spacecraft’s primary goal is to study more than 200,000 of the brightest stars for signs of planets circling them.
It will do this by looking for a dip in brightness, known as a transit.
Nasa predicts that Tess will discover 20,000 exoplanets, including more than 50 Earth-sized planets and up to 500 planets less than twice the size of Earth.
WHAT IS THE TESS SPACECRAFT?
NASA’s new ‘planet hunter,’ set to be Kepler’s successor, is equipped with four cameras that will allow it to view 85 per cent of the entire sky, as it searches exoplanets orbiting stars less than 300 light-years away.
By studying objects much brighter than the Kepler targets, it’s hoped TESS could uncover new clues on the possibility of life elsewhere in the universe.
Its four wide-field cameras will view the sky in 26 segments, each of which it will observe one by one.
In its first year of operation, it will map the 13 sectors that make up the southern sky.
Then, the following year, it will scour the northern sectors.
‘We learned from Kepler that there are more planets than stars in our sky, and now TESS will open our eyes to the variety of planets around some of the closest stars,’ said Paul Hertz, Astrophysics Division director at NASA’s Headquarters.
‘TESS will cast a wider net than ever before for enigmatic worlds whose properties can be probed by NASA’s upcoming James Webb Space Telescope and other missions.’
Tess is 5 feet (1.5 meters) wide and is shorter than most adults.
The observatory is 4 feet across (1.2 meters), not counting the solar wings, which are folded for launch, and weighs just 800 pounds (362 kilograms).
NASA says it’s somewhere between the size of a refrigerator and a stacked washer and dryer.
Tess will aim for a unique elongated orbit that passes within 45,000 miles of Earth on one end and as far away as the orbit of the moon on the other end.
It will take Tess two weeks to circle Earth.
‘They are going to be orbiting the nearest, brightest stars,’ Elisa Quintana, TESS scientist at NASA’s Goddard Spaceflight Center, told reporters last week.
‘We might even find planets that orbit stars that we can even see with the naked eye,’ she added.
‘So in the next few years we might even be able to walk outside and point at a star and know that it has a planet. This is the future.’
Just a couple of decades ago, the notion of finding habitable planets was a mere fantasy, said Paul Hertz, astrophysics division director at NASA.
‘Humans have wondered forever whether we were alone in the universe, and until 25 years ago the only planets we knew about were the eight in our own solar system,’ he told reporters on the eve of the Tess launch.
‘But since then, we have found thousands of planets orbiting others stars and we think all the stars in our galaxy must have their own family of planets.’
Tess, with its four advanced cameras, will scan an area that is 350 times larger than what Kepler studied, comprising 85 per cent of the sky in the first two years alone
Tess is designed as a follow-on to the US space agency’s Kepler spacecraft, which was the first of its kind and launched in 2009.
The ageing spacecraft is currently low on fuel and near the end of its life.
Kepler found a massive trove of exoplanets by focusing on one patch of sky, which contained about 150,000 stars like the Sun.
The Kepler mission found 2,300 confirmed exoplanets, and thousands more candidate planets. But many were too distant and dim to study further.
Tess, with its four advanced cameras, will scan an area that is 350 times larger, comprising 85 per cent of the sky in the first two years alone.
WHAT IS AN EXOPLANET?
Every star in the night sky likely plays host to at least one planet.
Worlds orbiting other stars are called ‘exoplanets,’ and they come in a wide variety of sizes.
Some are gas giants larger than Jupiter and some are small, rocky planets about as big around as Earth or Mars.
They can be hot enough to boil metal or locked in deep freeze.
They can orbit their stars so tightly that a ‘year’ lasts only a few days; they can orbit two suns at once.
Some exoplanets are sunless rogues, wandering through the galaxy in permanent darkness.
There are potentially trillions of planets in the Milky Way.
Our nearest neighboring star, Proxima Centauri, was recently found to possess at least one planet – probably a rocky one. It’s 4.5 light-years away – more than 25 trillion miles (40 trillion kilometers).
The vast majority of exoplanets have been found by searching for shadows: the incredibly tiny dip in the light from a star when a planet crosses its face. Astronomers call this crossing a “transit.”
‘By looking at such a large section of the sky, this kind of stellar real estate, we open up the ability to cherry-pick the best stars to do follow-up science,’ said Jenn Burt, a postdoctoral fellow at the Massachusetts Institute of Technology (MIT).
‘On average the stars that TESS observes are 30-100 times brighter and 10 times closer than the stars that Kepler focused on.’
Tess uses the same method as Kepler for finding potential planets, by tracking the dimming of light when a celestial body passes in front of a star.
The next step is for ground-based and space telescopes to peer even closer.
Tess uses the same method as Kepler for finding potential planets, by tracking the dimming of light when a celestial body passes in front of a star. By focusing on planets dozens to hundreds of light-years way, Tess may enable future breakthroughs
The Hubble Space Telescope and the James Webb Space Telescope, scheduled to launch in 2020, should be able to reveal more about planets’ mass, density and the makeup of their atmosphere – all clues to habitability.
‘Tess forms a bridge from what we have learned about exoplanets to date and where we are headed in the future,’ said Jeff Volosin, Tes project manager at Nasa’s Goddard Spaceflight Center.
By focusing on planets dozens to hundreds of light-years way, TESS may enable future breakthroughs, he said.
‘With the hope that someday, in the next decades, we will be able to identify the potential for life to exist outside the solar system.’
WHAT WERE KEPLER’S TOP FIVE DISCOVERIES?
Launched in 2009, the Kepler telescope has helped in the search for planets outside of the solar system.
The satellite typically looks for ‘Earth-like’ planets, meaning they are rocky and orbit within the that orbit within the habitable or ‘Goldilocks’ zone of a star.
If a planet sits within a habitable zone it means it is not too hot or too cold for water to have formed at the planet’s surface, one of the key conditions for life.
While the planet has found thousands of exoplanets during its eight-year mission, five in particular have stuck out.
Kepler-452b, dubbed ‘Earth 2.0’, shares many characteristics with our planet despite sitting 1,400 light years away. It was found by Nasa’s Kepler telescope in 2014
1) ‘Earth 2.0’
In 2014 the telescope made one of its biggest discoveries when it spotted exoplanet Kepler-452b, dubbed ‘Earth 2.0’.
The object shares many characteristics with our planet despite sitting 1,400 light years away.
It has a similar size orbit to Earth, receives roughly the same amount of sun light and has same length of year.
Experts still aren’t sure whether the planet hosts life, but say if plants were transferred there, they would likely survive.
2) The first planet found to orbit two stars
Kepler found a planet that orbits two stars, known as a binary star system, in 2011.
The system, known as Kepler-16b, is roughly 200 light years from Earth.
Experts compared the system to the famous ‘double-sunset’ pictured on Luke Skywalker’s home planet Tatooine in ‘Star Wars: A New Hope’.
The Trappist-1 star system (artist’s impression), which hosts a record seven Earth-like planets, was one of the biggest discoveries of 2017. Kepler spotted the system in 2016, but scientists revealed the find in a series of papers released in February this year
3) Finding the first habitable planet outside of the solar system
Scientists found Kepler-22b in 2011, the first habitable planet found by astronomers outside of the solar system.
The habitable super-Earth appears to be a large, rocky planet with a surface temperature of about 72°F (22°C), similar to a spring day on Earth.
4) Discovering a ‘super-Earth’
The telescope found its first ‘super-Earth’ in April 2017, a huge planet called LHS 1140b.
It orbits a red dwarf star around 40 million light years away, and scientists think it holds giant oceans of magma.
5) Finding the ‘Trappist-1’ star system
The Trappist-1 star system, which hosts a record seven Earth-like planets, was one of the biggest discoveries of 2017.
Each of the planets, which orbit a dwarf star just 39 million light years, likely holds water at its surface.
Three of the planets have such good conditions that scientists say life may have already evolved on them.
Kepler spotted the system in 2016, but scientists revealed the discovery in a series of papers released in February this year.