- 4285 - MARS - discoveries! InSight was able to collect over four years of data before it ran out of power in December 2022. The new study examined measurements taken from the mission's first 900 days on Mars enough time to pick up on even subtle changes in planetary spin.
------------------------- 4285 - MARS - discoveries!
- NASA's InSight
mission shows that Mars's rotation is speeding up and its days are growing
slightly shorter. Like an ice skater
tucking their arms for an elegant spin, the planet Mars appears to be rotating
slightly faster with each passing year.
-
- The Red Planet's
spin is accelerating at a rate of 4 milliarcseconds, one one-thousandth of an
arcsecond, per year. As a result, the length of a Martian day is getting
shorter by fractions of a millisecond annually.
-
- By bouncing radio
waves into space and assessing how long they took to get back to the surface of
the planet, InSight painted a detailed portrait of the planet's spin.
-
- Scientists aren't
sure what's causing the acceleration, but they have a few ideas. One is that
ice accumulation at the planet's poles is causing a slight change in how its
mass was distributed. Or, the researchers hypothesize, it could be due to a
phenomenon called post-glacial rebound, where landmasses rise up after
millennia buried under the ice.
-
- In addition to
tracking the planet's spin, InSight's data provided an unprecedented look into
Mars's core. Upon analyzing it, researchers discovered that the Martian core
has a radius of about 1,150 miles, smaller than Earth's 2,165 mile core, but
larger in proportion to the planet.
-
- The study also
revealed that this core is not uniform. Instead, it has regions of higher or
lower density, causing its molten material to "slosh" as Mars spins.
This could be another possible reason for the Red Planet's accelerated spin.
-
- Curiosity Rover
captured a 360-degree panorama while parked below Gediz Vallis Ridge, a
formation that preserves a record of one of the last wet periods seen on this
part of Mars.
-
- Curiosity has
spent three years trying to reach this spot on Mars. About three billion years ago, rushing
water on Mars carried mud and boulders down a steep slope and deposited them
into a vast fan-shaped debris pile.
Curiosity Rover has been trying to reach a ridge overlooking the region,
and now finally, the rover has reached this vantage point after three years of
climbing.
-
- Getting to this
location, called Gediz Vallis Ridge, was not easy. For Curiosity it took three
different attempts to reach the top of the ridge. Previous attempts were thwarted by
knife-edged “gator-back” rocks and extremely steep slopes. Scientists and
engineers said this was one of the most difficult climbs of the mission to
date. Curiosity arrived at the ridge on August 14, 2023 and now is finally
studying this area.
-
- The overarching
goal of the mission has been to climb the lower part of 3-mile-tall Mount
Sharp. Ever since the rover landed in Gale Crater on Mars, it has discovered
evidence of ancient lakes and streams along the way. As the rover ascends the
mountain, each layer provides a history of different Martian eras.
-
- As Curiosity
ascends, scientists are learning how the landscape changed over time. Gediz
Vallis Ridge was among the last features on the mountain to form, making it one
of the youngest geological time capsules.
-
- The rover has been
studying rocks by taking photos and sending them to Earth, and using the
instruments on its robotic arm to studying them even deeper. The photos have
provided scientists the first up-close views of the eroded remnants of a
geologic feature known as a debris flow fan, where debris flowing down the
slope spreads out into a fan shape. Debris flow fans are common on both Mars
and Earth, but scientists are still learning how they form.
-
- Perseverance Rover
just rolled past a big milestone on the Red Planet. The car-sized Perseverance has now been
exploring its exotic environs for 1,000 Mars days, or sols. (One sol is
slightly longer than an Earth day, 24 hours and 37 minutes.)
-
- Perseverance and
its tiny robotic partner, the Ingenuity helicopter, landed inside Mars' Jezero
Crater on February 18, 2021. Ever since, the big rover has been hunting for
signs of ancient Mars life on the floor of the 28-mile-wide Jezero.
-
- Orbital imagery of
this site showed a delta, clear evidence that a large lake once filled the
crater. A lake is a potentially
habitable environment, and delta rocks are a great environment for entombing
signs of ancient life as fossils in the geologic record.
-
- That history
begins about four billion years ago, when an asteroid impact formed the
crater. Perseverance has found that
Jezero's floor is made of volcanic rock. Sandstones and mudstones atop that
basal layer show that a river started flowing into Jezero, and depositing
sediments there, a few hundred million years after the crater's formation.
-
- That flow
eventually formed a large lake — one that got as wide as 22 miles, with a
maximum depth of perhaps 100 feet. The
delta is also studded with boulders, which originated outside Jezero; they were
carried in by powerful torrents.
-
- Perseverance is
also collecting and caching samples, which will be returned to Earth by a joint
NASA-European Space Agency campaign in the 2030s, if all goes according to
plan.
-
- One sample called
'Lefroy Bay' contains a large quantity of fine-grained silica, a material known
to preserve ancient fossils on Earth.
Another, 'Otis Peak,' holds a significant amount of phosphate, which is
often associated with life as we know it. Both of these samples are also rich
in carbonate, which can preserve a record of the environmental conditions from
when the rock was formed.
-
- Ingenuity is
celebrating the 1,000-sol milestone too and the 4-pound chopper's staying power
is a bit surprising. Ingenuity is a technology demonstrator; its prime mission
called for a five-flight campaign, to show that aerial exploration is possible
on Mars despite the planet's thin atmosphere.
-
- Ingenuity aced that
task in the spring of 2021, then was granted a mission extension to serve as a
scout for Perseverance. The rotorcraft has completed 62 flights on this
extended mission so far, and it remains active to this day.
-
-
December 23, 2023
MARS -
discoveries!
4285
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