Page 15 - BBC Sky at Night - September 2017 UK

BULLETIN SEPTEMBER 15

Milky Way has distant origins NEWS IN

BRIEF
Half of the Galaxy may have started a million lightyears from home

Fifty per cent of the atoms in this magazine, your
body, and everything else in the Milky Way could
have started life in another galaxy, according to
the latest research into intergalactic winds.
These powerful streams blow at hundreds
of kilometres per second between galaxies, SPRITES FIRED
transferring matter between them. New computer INTO ORBIT
simulations have revealed that as much as half The smallest ever
of the Milky Way’s matter could have been satellite, weighing only
brought into our Galaxy by this process. 4g, has successfully
“Our origins are much less local than we made contact with the
previously thought,” says Prof Claude-André ground from low-Earth
Faugher-Giuguère, from Northwestern University orbit. The tiny spacecraft,
Half of the atoms that and who took part in the research. “This study named Sprites, are only
make up everything we gives us a sense of how things around us are 3.5cm long yet contain
know could have emigrated connected to distant objects in the sky.” a solar panel, radio
here from somewhere else transmitter and several
www.northwestern.edu
sensors. They were
developed for the
New Horizons asteroid may be a pair Breakthrough Starshot
project, which aims to
send a fleet of
NASA’s New Horizons probe, which previously nanospacecraft to
Alpha Centauri within
flew past Pluto, could be heading towards not
the next few decades.
just one target, but two. On 10 July its current
destination, asteroid 2014 MU69, passed in
front of a distant star. Observations of this
occultation revealed that the space rock is
either elongated or is in fact two bodies orbiting
closely – perhaps even touching.
“This new finding is simply spectacular. The
shape of MU69 is truly provocative, and could
mean another first for New Horizons going to a PLANET HUNT
binary object in the Kuiper Belt,” says Alan Stern, AT BARNARD’S
New Horizons’ principal investigator. “I could not A new planet hunt
began on 16 July,
be happier with the occultation results, which
when the Arecibo radio
promise a scientific bonanza for the flyby.” ! 2014 MU69 could be two space rocks posing as one, telescope turned its
www.sofia.usra.edu as illustrated here; alternatively, it could just be very long
eyes towards Barnard’s
Star, the second closest
star system to Earth
LOOKING BACK THE SKY AT NIGHT after Alpha Centauri.
There have been
previous hints that a
28 September 1976 super-Earth planet
exists in a ‘cold’ orbit
On 28 September 1976, The Sky The landers were stationed far out from the star,
at Night looked at the first science on opposite sides of the planets. beyond the habitable
results from the Viking landers, They sent back over 1,400 images zone. The team will
the first probes to successfully of the surface, as well as conducting now scour the Arecibo ESA/HUBBLE & NASA, NASA/JHUAPL/SWRI/ALEX PARKER, NASA/JPL, NASA/ESA/STSCI/G. BACON
touch down on the surface of chemical, seismological and data looking at the
Mars and send back data. meteorological tests. One of emissions from the
Two missions – both consisting these looked for living microbes star, such as those
of a lander and an orbiter – were on the planet and at first appeared caused by flares.
sent to Mars and both made it to to be positive. The result was From these, the team
the Red Planet’s surface. The quickly discounted as having will characterise the
orbiters managed to map all of a non-biological origin, though radiation and magnetic
Mars’s surface to a resolution of the debate over whether Viking environment, looking
150m per pixel, the most complete detected life still continues over ! The Viking landers provided our for any perturbations
view of the Red Planet at the time. 40 years later. first close glimpses of Martian terrain
that could be caused
by planets.

skyatnightmagazine.com 2017