2 November 2019 | New Scientist | 5CALIFORNIA is burning yet again.
As New Scientist went to press,
nearly 200,000 people had been
ordered to evacuate as strong
winds fanned wildfires.
Meanwhile, the electricity
supply is being turned off in
some areas to avoid faulty cables
sparking more fires, with a power
company warning that as many as
3 million people could be affected.
The Getty fire near Los Angeles
and the Kincade fire near San
Francisco are the latest in a series of
huge wildfires in the state in recent
years. “The last three years feel so
far outside of my lived experience
I almost can’t comprehend it,”
tweeted Abigail Swann, a climate
researcher at the University of
Washington, Seattle. She grew upin Sonoma county, where the
Kincade fire (pictured) is raging.
Wildfires are a natural
occurrence in California, but
global warming is making
conditions in some areas drier,
so when fires do happen, they can
become bigger. The average area
in California burned by wildfires
each year is now five times larger
than it was in the 1970s.
Some researchers also think
that global warming is sometimes
resulting in stronger winds,
and it is during high winds
that fires are most likely to
grow and become dangerous.The global picture is similar.
The overall number of wildfires
isn’t going up, but larger areas are
burning, according to the World
Meteorological Organization.
The worst wildfire in California’s
history – the Camp fire in
November 2018 – seems to have
been caused by sparks from
faulty overhead power cables.
That means that the company
responsible for maintaining them,
Pacific Gas & Electric, could be
liable for damages. The firm is now
turning off electricity supplies in
areas where there is a high risk of
wildfires due to strong winds. ❚For the third year in a row, the US state is being hit by devastating
wildfires, leading to mass evacuations, reports Michael Le PageSolar systemNew dwarf planet
is smallest ever
IT IS time to add a new dwarf
planet to the docket. The
best images yet of asteroid
Hygiea show that it is almost
spherical, a key requirement
to be upgraded to being a
dwarf planet, the most
famous of which is Pluto.
Hygiea, in the asteroid belt,
was discovered in 1849, but
we have never before been
able to get high-resolution
pictures of it. Now images
taken by Miroslav Brož at
Charles University in Prague,
Czech Republic, and his
colleagues using the Very
Large Telescope in Chile have
revealed its true shape, and
it is much more spherical
than we thought (Nature
Astronomy, doi.org/ddbq).
At a bit more than
430 kilometres across,
that would make Hygiea
the smallest dwarf planet
we have found, less than
half the diameter of the
next-smallest one.
According to simulations
by Brož and his colleagues,
Hygiea seems to have
formed in an enormous
collision that broke apart
a larger body. The fragments
then coalesced into a sphere,
rather than the body slowly
changing shape over time.
Hygiea won’t officially
be a dwarf planet until it is
certified by the International
Astronomical Union. Brož
says this may prompt a
rethink of the definition
of dwarf planets. Although
the asteroid satisfies all
existing criteria, its violent
formation makes it
different from the other
dwarfs, which formed more
peacefully. ❚ Leah CraneWildfires grip California
News
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