Page 102 - BBC Sky at Night - September 2017 UK

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RATINGS

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New astronomy and space titles reviewed HHHHH Avoid

The Planet TWO MINUTES WITH
Elizabeth Tasker
Factory
Exoplanets and What can the study
of other planetary
the search for systems tell us about
a second Earth our Solar System?
One example is planet
Elizabeth Tasker migration, where a
Bloomsbury Sigma young planet changes its orbit to be
£16.99 z HB closer or farther from the star. This was
known about since the 1980s, but our
Solar System showed little evidence of it
There’s an old Indian fable called ‘The
Blind Man and the Elephant’, in which six happening. It was assumed that migration
was not important in shaping a planetary
blind men examine an elephant. One finds similar to Earth, and the possibility of
the smooth membrane of the elephant’s the existence of other life forms. Tasker system. This changed with the discovery
ear, the other a carved tusk. Another clearly knows her field very well, sharing of exoplanets, which commonly show
grasps the tail. Each is correct and yet stories of the countless discoveries of strong evidence of major rearrangements.
none has properly described the elephant. exoplanets in the past 20 years, starting The question then became “Why didn’t
The same can be said of the current state in 1995 with 51 Pegasi b. our planets move more?”, with an answer
of play in astronomy and the rapidly Detailing all the ingredients necessary that may lie in Jupiter and Saturn
growing field of exoplanet research: with for stable planetary systems, how they anchoring one another.
more than 4,600 exoplanets are formed, their structures
detected (and counting) and features, The Planet What are some of the strangest
since 2002, are we any Factory is packed with exoplanets we have discovered so far?
closer to seeing the interesting insights The first discovered were some of the
Universe for what it and scientific content strangest. Huge hot Jupiters should not
truly is, or are we that capably captures be able to form so close to their star, so
blindly making the current state of how did they get there? Or the planets
conclusions based on exoplanet research. around the dead corpses of stars known
a series of observations? However, it does as pulsars: did they form when the
That is the premise of feel repetitive at pulsar was a regular star, or are they
this book, which times and there is the grizzly rebirth of a star that the
attempts to summarise almost an overload of pulsar ripped into pieces?
this vast field of research. detail. We leave with
Starting with the early many new observations Which is your favourite?
Universe and the building We’re detecting more and that collectively support It might be 55 Cancri e. It is about twice
blocks that were necessary more exoplanets, but the the argument that the size of Earth, with an orbit lasting just
for planet formation, big picture eludes us planetary systems exist 18 hours. It could be a highly volcanic
Elizabeth Tasker chronicles the around pretty much every star, but the lava world covered in molten magma,
exoplanetary detection methods of the bigger question of our place in the Universe or with an ocean consisting of a strange
past, and new techniques currently applied and how it all weaves together remains state of water that is neither liquid nor
for more rapid and accurate detection, the unsolved. In this relatively new field of gas. It could even have a mantle of
success of the Kepler space telescope in astronomy, we are still blind to that one. diamond and seas of tar.
advancing the discovery of exoplanets in the HHHHH
‘Goldilocks zone’ (not too far and not too ELIZABETH TASKER is an astrophysicist
ISTOCK near from the star) that could potentially NIAMH SHAW is an engineer and and an associate professor at the
space science communicator
Japanese Aerospace Exploration Agency
support life with water and atmospheres
skyatnightmagazine.com 2017