Page 108 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

How are exoplanets

Discover how we are able to spot alien
found? worlds now and in the future

cientists had suspected that exoplanets your own back garden with a few specialised discovery of many others, but it isn’t the most
– planets beyond our Solar System – had pieces of astronomy kit and particularly dark successful exoplanet hunter. That particular
Sexisted for several hundred years, long night skies. gong goes to NASA’s Kepler spacecraft, a
before the fi rst confirmed detection was made. It’s not surprising, however, that it’s the big specialised alien-world hunter that

Over the years some claimed to have ground-based and space observatories run by successfully passed the 1,000 confi rmed
discovered an exoplanet, but it wasn’t until various government agencies and exoplanets milestone earlier this year.
1992 that the detection of a planetary-mass organisations around the world, that have Of course, the total number of exoplanets
object orbiting a type of star – known as a made nearly 2,000 confirmed detections to we’ve discovered so far is a drop in the ocean:

millisecond pulsar – was confi rmed. date. Most of these discoveries have been made the Gaia telescope was launched in late 2013 to
That observation took the power of the giant by space telescopes at their vantage point 1.5 map a billion stars, or about one per cent of our
Arecibo radio telescope in Puerto Rico and million kilometres (932,057 miles) away from own galaxy, and will help in the search for new

some out-of-the-box thinking to detect – Earth’s obscuring atmosphere. Hubble, which worlds by finding the host stars that they orbit.
techniques that are now standard procedure had been in orbit for two years by the time the However, given that there’s an estimated

in the search for distant worlds. But it’s first exoplanet was confirmed, has discovered average of one planet for every star in the

actually possible to detect exoplanets from a handful of these and has contributed to the Milky Way, we’ve still got a long way to go.

Exoplanet hunting

These are – or will be – the most
powerful telescopes searching
for new worlds
Spitzer Space Telescope
With a few clever hardware
adjustments, this infrared
instrument has been
repurposed as a planet hunter.
The Hubble Space
Telescope Kepler space
Hubble is a valuable asset in observatory
exoplanet hunting, but its Despite a failure that
technology is old and will threatened the entire mission,
soon be decommissioned. Kepler has continued planet
hunting and has clocked up the
most confi rmed exoplanet
discoveries to date.

Terrestrial observatories
The European Southern
Observatory (ESO) in Chile has
some of the best ground-based
telescopes in the world.

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How It W

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