Paris (AFP)
- France is set to launch a champagne box-sized mini satellite into Earth orbit
on Friday to study a mysterious, juvenile planet system in our Milky Way
galaxy, mission controllers said.
The PicSat
orbiter's target is the massive star Beta Pictoris, some 60 light years from
Earth in the southern constellation of Pictor (The Painter's Easel), and its
planet Beta Pictoris b -- a gassy giant.
Built at
the Paris Observatory's LESIA laboratory, with European backing, PicSat is due
to be launched in the early-morning hours of Friday on an Indian PSLV rocket.
It will
orbit our planet at an altitude of some 500 kilometres (310 miles), hoping to
learn more about Beta Pictoris b by observing the next time it transits its
host star, appearing as a dot on the bright surface as seen from Earth's
perspective.
This
once-in-18-year transit is expected some time in 2018, mission leader Sylvestre
Lacour, an astrophysicist at France's CNRS research institute, told AFP.
"We
are not 100-percent sure that the transit will happen" during PicSat's
one-year lifetime, he said, as "the orbit of Beta Pictoris b is not
well-known."
If not,
"we will observe other, secondary objects orbiting the star."
By
measuring how much light a planet blocks out as it transits its star,
astronomers can glean details about its size and the composition of its
atmosphere.
PicSat
measures 10x10x30 centimetres (4x4x12 inches), "the size of a champagne
box", said Lacour.
Planet in
a spin
It comes
equipped with a telescope for fact-gathering, and solar panels to power all its
systems. Weighing in at 3.5 kilogrammes (7.7 pounds), the satellite's power
consumption is a mere 5 W, similar to that of an economical light bulb.
Discovered
in 1984, Beta Pictoris has a mass about 1.8 times that of our Sun.
It is young
in astronomical terms -- only about 20 million years old compared to the Sun's
4.5 billion years.
It is
surrounded by a huge disc of gas and dust -- the materials from which planets,
asteroids and comets are formed -- making it an ideal subject for studying the
mechanism by which solar systems evolve.
Beta
Pictoris b is about 16 times larger and 3,000 times more massive than Earth,
with days lasting about eight hours. It orbits its star at a distance eight
times that of Earth to the Sun.
In 2014,
scientists said it spins at a breakneck speed of some 25 kilometres per second
(90,000 kph or 56,000 miles per hour).
No comments:
Post a Comment