12 ASTRONOMY • FEBRUARY 2022
NASA TESTS
SPACESUITS
FOR ARTEMIS
No, this isn’t space art — it’s
Oregon. In August 2021,
NASA’s Haughton-Mars
Project tested a series of new
spacesuit technologies at a set
of sites in Oregon where the
terrain mimics the landscapes
of the Moon and Mars. Some
of the locations had been
previously used to train Apollo
astronauts. Others were chosen
to ref lect unique environments
that Artemis astronauts are
expected to explore — like
lunar pits and caves in ancient
lava tubes, represented by
Skylight Cave in Deschutes
National Forest, pictured here.
Technologies tested included
displays embedded in helmets
for astronauts to track their
health status and checklists,
and smart gloves that would
allow wearers to control
robotic machinery with hand
gestures. — M.Z.QUA N T U M GR AVIT Y
Researchers chose Jezero Crater
as the landing site for NASA’s
latest Mars rover, Perseverance, because
the site appeared to be an ancient
lake that was fed by a river roughly
3.7 billion years ago. Now, mission
scientists have confirmed this — and
also found that the region experienced
f lash f loods, carrying boulders into the
lake from up to tens of miles away.
The research, published Oct. 7 in
Science, is based on images the rover
took in the first three months after
landing in Jezero Feb. 18, 2021. Its cam-
eras zoomed in on two regions roughly
1.3 miles (2.2 kilometers) distant with
exposed rocky outcrops.
One of these features, named
Kodiak, is a butte west of the rover
with exposed rock layers up to 80 feet
(25 meters) high. Several places on the
butte feature a distinct structure: a set
of layers at a slanted angle, sandwiched
between parallel rock layers above and
below.
These slanted rock layers, known as
foresets, are characteristic of former
river deltas. As a river dumps mud and
clay into a body of water, that sediment
forms an underwater fan-shaped
mound that drops off sharply away
from shore. Those submerged slopes
eventually become angled rock layers.“This is the key observation that
enables us to once and for all confirm
the presence of a lake and river delta
at Jezero,” said Nicolas Mangold, the
paper’s lead author and a researcher
at the Laboratories de Planétologie et
Géodynamique in Nantes, France, in
a statement.
Perseverance also imaged four
outcrops on the wall of the river delta
itself, which rises 200 feet (60 m)
above the crater f loor. Its lower levels
are made of fine-grained, angled rock
layers, similar to those at Kodiak. But
on top of them was a surprise: a rock
layer containing “boulders up to 5 feet
[1.5 m] across that we knew had no
business being there,” said Mangold.
Evidently, the river f lowed steadily
in its early years, building up the delta’s
lower layers. But at some later time, it
experienced episodes of f lash f looding
— perhaps triggered by intense rainfall
or volcanoes suddenly melting snow —
capable of carrying the boulders.
The findings will also help mission
planners. To search for samples that
may harbor signs of ancient life, the
team will guide Perseverance to the
fine-grained material in the lower rock
layers, as the steady buildup of material
may have preserved organic matter or
other biosignatures. — MARK ZASTROWMartian floods filled
Jezero Crater
LOST LAKE. An illustration shows how Jezero Crater’s lake was fed by a river flowing in from its
northwest (upper left), while overflow streamed out of a channel at the lake’s eastern edge (at right).
NASA/JPL-CALTECH NASA HAUGHTON-MARS PROJECT/PASCAL LEE