18 | New Scientist | 19 October 2019HealthMove over Jupiter,
Saturn is moon kingTHE solar system has a new
champion. The discovery of 20
additional satellites around Saturn
means the ringed giant has passed
Jupiter as the planet with the most
known moons: 82 to Jupiter’s 79.
The new additions are all about
5 kilometres across. They were
spotted by a team led by Scott
Sheppard at Carnegie Institution
for Science in Washington DC.
Only three of the 20 moons areBadger cull to avert
TB could backfireTHE controversial killing of
thousands of badgers to prevent
them spreading disease to cattle
risks making it worse. The animals
roam further when culling begins,
raising the chance of transmission.
The UK government has been
working with farmers since 2013
to shoot badgers across England
in a bid to reduce the spread of
bovine tuberculosis (TB) to cattle
farms. Infected cows must be
destroyed, which costs the
government around £100 million
a year in compensation. Last
month, the cull was expanded.
Scientists have warned of
unintended negative side effects
from culling for years. Now, a team
led by Cally Ham at the Zoological
Society of London has found that
badgers increased the area they
range in by 61 per cent after culling
started, increasing the risk of
bovine TB reaching cattle. “WeWildlife^ SpacePEOPLE who eat home-cooked
meals have lower levels of
potentially harmful chemicals in
their blood. Tools used to prepare
restaurant and takeaway meals and
some packaging may be to blame.
PFAS, short for perfluoroalkyl
and polyfluoroalkyl substances,
are a group of synthetic chemicals
that are resistant to heat and don’t
easily degrade. Because of this,
they are used in some cookware
and stain-resistant materials.
Studies in the US have found
the chemicals in the blood of 97 to
100 per cent of adults and children.
Diet is thought to be a key factor. To
investigate further, Laurel Schaider
at the Silent Spring Institute in
Massachusetts looked at how
eating habits affect PFAS levels.
Schaider and her colleagues
analysed data from more than10,000 participants in the US
National Health and Nutrition
Examination Survey from 2003 to- Participants provided blood
and information on food sources.
PFAS were detected in three out
of every four samples. Levels were
lower in those who ate more meals
at home, and higher among those
who ate out or ate more fast food.
For every 1000 kilocalories of
food eaten from non-restaurant
sources each day, the concentration
of PFAS dropped by up to five per
cent. Microwave popcorn raised
levels, possibly due to chemicals in
packaging (Environmental Health
Perspectives, doi.org/dcg2).
There is some evidence to
suggest PFAS may cause cancer
and weight gain, and affect fertility,
child development and the immune
system. Ruby Prosser Scully
Eating out can bring a side
serving of suspect chemicals
prograde, meaning they orbit
Saturn (pictured) in the same
direction as the planet spins. Of
the rest, one has the widest orbit
of any of Saturn’s known moons.
Most of the objects seem to
be clustered in two groups, each
of which probably came from a
parent moon that was smashed
apart. Two of the prograde moons
have the tightest orbits of the new
haul, taking about two years to
circle Saturn. All the others take
more than three years.
As we find more of these small
moons, we also learn about the
larger parent moons that orbited
earlier in our solar system’s
history. That can help us figure out
how the planets formed and what
their environments were like then.
There is now a competition to
name the moons, with specific
rules. Two must be named after
giants from Inuit mythology.
Another 17 must be named after
giants from Norse lore. And one
must be named after a giant from
Gallic mythology. Leah Craneknow that direct badger to cattle
contact is rare,” says Ham. “But if
the badger goes in more fields, it
could spread its infection further,
through defecation or urination.”
She also discovered that badgers
spent around an hour and a half
less outside their setts each night
after culling began, making the
cull harder. The reason may be
that, with fewer badgers around,
food is more plentiful and
successful hunts take less time.
Previous studies had suggested
that badgers move around more
in response to a cull, but had only
looked at badgers before and after
the cull. In contrast, Ham and her
team fitted trackers to 67 badgers
in north Cornwall between 2013
and 2017. Their study is the first to
observe real-time movements of
individual badgers (Journal of
Applied Ecology, doi.org/dcgn).
Ham says vaccinating badgers
avoids the problems a cull brings.
Efforts are under way to start a
large vaccination programme
in Cornwall. Adam VaughanTHE PICTURE PANTRY / ALAMY STOCK PHOTO
NASANews In brief