New Scientist - USA (2019-10-05)

(Antfer) #1

14 | New Scientist | 5 October 2019


NASA astronaut Christina Koch
captured this image of a Soyuz
rocket making its way to the
International Space Station –
from onboard the ISS.
“What it looks like from
@ Space_ Station when your
best friend achieves her lifelong
dream to go to space,” Koch
tweeted. “Caught the second
stage in progress!”
The rocket was carrying Koch’s
friend, the NASA flight engineer
Jessica Meir. Also on board were
Oleg Skripochka from the Russian
space agency Roscosmos and Hazza
Ali Almansoori from the United Arab
Emirates. Almansoori is the first
person from the UAE to go to space.
The five other people on the
ISS with Koch gathered to watch
the approach. Andrew Morgan,
a NASA astronaut, tweeted: “All six
members of #Expedition60 packed
into the cupola, our window on the
Earth, to see this rare spectacle”.  ❚

International Space Station

WE FINALLY have hard evidence
that the oldest rocks in Australia
contain fossils of living things.
Dating back nearly 3.5 billion
years, they are the oldest known
microorganisms.
Raphael Baumgartner at the
University of New South Wales
in Australia and his colleagues
looked at rocks in the Pilbara
region of Western Australia.
This area has some of the oldest
preserved rocks on Earth, such
as the Dresser Formation,
which is 3.48 billion years old.
The formation appears
to contain structures called
stromatolites. These form when
microbes grow in layers and are
covered in sediment. Yet many

researchers have argued that these
Pilbara rock structures aren’t
stromatolites and could have
formed without life.
Baumgartner and his colleagues
drilled into the rocks to extract
samples. These contained
“exceptionally preserved organic
matter”, he says, including strands
of the sort seen when microbes
form slimy layers called biofilms.
Multiple chemical analyses
indicated that this matter came
from living organisms (Geology,
doi.org/db2s).
“We have found smoking gun
evidence for some of the earliest
life on Earth,” says Baumgartner.
“There are no convincing
organic matter or microbial

remains older than ours.”
There are claims of older fossils
or chemical traces of life, some
dating to more than 4 billion years
ago, but none are widely accepted.
The organic matter that
Baumgartner and his colleagues
found was mostly trapped inside
a mineral called pyrite or fool’s
gold, which is based on iron
and sulphur. “The pyrite is

extraordinary,” says Baumgartner.
Because the microbes are so well-
preserved, it must have formed
quickly – perhaps even while
they were alive.
Some modern microbes live
off sulphur and produce pyrite
as a waste product. The Dresser
Formation microbes may have
done the same, says Baumgartner.
“They’ve done a good job,”
says Lindsay Hays, who works
for NASA’s Astrobiology Institute
in Washington, DC. She says she
can’t say for certain that the
study’s conclusions are correct,
but the fact it is based on
multiple techniques makes
it more reliable.  ❚

Palaeontology

Earth’s earliest microbes found in rocks


Donna Lu

A stromatolite
rock structure
in Western
Australia

Welcome to space


Astronaut snaps the rocket carrying her best friend into orbit


CH

RIS

TIN

A^ K

OC
H/A

P/S

HU

TT
ER
ST
OC

K

News


AU

SC
AP

E/G

ET
TY
IM

AG

ES

Michael Marshall
Free download pdf