February 4th, 2020

Weird clumps of air that disrupt radio signals found on Mars

NASA’s MAVEN spacecraft has found signs of layers and rifts in the Martian atmosphere

Earth’s upper atmosphere has strange dense layers of ions that are constantly appearing and disappearing and which can hamper radio communication. Now, the same thing has now been found on Mars, offering a new chance to crack understand this poorly studied phenomenon.

The ionosphere is the layer of the atmosphere about 60 to 1000 kilometres up that is full of charged particles. When those particles are temporarily blown into clumps by the wind, they form what researchers call sporadic E layers in the lower reaches of the ionosphere.

“They act like a mirror in the sky, and radio signals bounce off of them,” says Glyn Collinson at NASA’s Goddard Space Flight Center in Maryland. “When you turn on your favourite radio station and it’s jammed by another station, you have probably been the victim of a sporadic E layer.”

They don’t just interfere with commercial radio stations, though – they can also block radar signals that are used to detect aircraft and ballistic missiles, he says.

E layers are difficult to study on Earth, because they appear and disappear unpredictably and they are at an altitude that is too high for aircraft to reach and too low for satellite orbits. But Collinson and his colleagues have spotted them in the Martian atmosphere for the first time, where they might be far easier to study.

The team found signs of 34 E layers in data from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. The layers form higher in the Martian atmosphere, so MAVEN is flying right through them and they are probably too high to interfere with any future radio communications on the ground, Collinson says.

August 27th, 2019

Mars Missions Stop in Their Tracks as Red Planet Drifts to the Far Side of Sun

This animation illustrates Mars solar conjunction, a period when Mars is on the opposite side of the Sun from Earth. During this time, the Sun can interrupt radio transmissions to spacecraft on and around the Red Planet. Credit: NASA/JPL-Caltech

All of NASA’s spacecraft on Mars are about to find themselves on their own, running simplified routines and cut off from their masters on Earth. That’s because something big is about to come between the two planets — an electromagnetic energy source that’s too powerful to broadcast through or around: the sun.

During this period, known as the Mars solar conjunction, our home star and its corona pass between Earth and the Red Planet. Some radio signals might still get through, according to a statement from NASA’s Jet Propulsion Laboratory (JPL), but they aren’t reliable. Fortunately for all those distant robots, NASA knows this happens every couple years, and the machines are well prepared for the coming quiet period.

“Our engineers have been preparing our spacecraft for conjunction for months,” Roy Gladden, manager of the Mars Relay Network, said in the statement. “They’ll still be collecting science data at Mars, and some will attempt to send that data home. But we won’t be commanding the spacecraft out of concern that they could act on a corrupted command.”

June 18th, 2019

Meteors help Martian clouds form

This image, taken from a computer simulation, shows middle altitude clouds on Mars. (Courtesy Victoria Hartwick)

How did the Red Planet get all of its clouds? CU Boulder researchers may have discovered the secret: just add meteors.

Astronomers have long observed clouds in Mars’ middle atmosphere, which begins about 18 miles (30 kilometers) above the surface, but have struggled to explain how they formed.

Now, a new study, which will be published on June 17 in the journal Nature Geoscience, examines those wispy accumulations and suggests that they owe their existence to a phenomenon called “meteoric smoke”—essentially, the icy dust created by space debris slamming into the planet’s atmosphere.

The findings are a good reminder that planets and their weather patterns aren’t isolated from the solar systems around them.

“We’re used to thinking of Earth, Mars and other bodies as these really self-contained planets that determine their own climates,” said Victoria Hartwick, a graduate student in the Department of Atmospheric and Ocean Sciences (ATOC) and lead author of the new study. “But climate isn’t independent of the surrounding solar system.”

The research, which included co-authors Brian Toon at CU Boulder and Nicholas Heavens at Hampton University in Virginia, hangs on a basic fact about clouds: They don’t come out of nowhere.

“Clouds don’t just form on their own,” said Hartwick, also of the Laboratory for Atmospheric and Space Physics at CU Boulder. “They need something that they can condense on to.”

On Earth, for example, low-lying clouds begin life as tiny grains of sea salt or dust blown high into the air. Water molecules clump around these particles, becoming bigger and bigger until they form the large puffs that you can see from the ground.

But, as far as scientists can tell, those sorts of cloud seeds don’t exist in Mars’ middle atmosphere, Hartwick said. And that’s what led her and her colleagues to meteors.

July 23rd, 2018

NASA’s MAVEN Spacecraft Finds That “Stolen” Electrons Enable Unusual Aurora on Mars

MAVEN observations of a proton aurora. In the top panel, natural variability of the solar wind results in occasional dense flows of solar wind protons bombarding Mars. At bottom, observations by MAVEN’s Imaging Ultraviolet Spectrograph show increased ultraviolet emission from the atmosphere when the solar wind is enhanced.
Credits: NASA/MAVEN/University of Colorado/LASP/Anil Rao

Auroras appear on Earth as ghostly displays of colorful light in the night sky, usually near the poles. Our rocky neighbor Mars has auroras too, and NASA’s MAVEN spacecraft just found a new type of Martian aurora that occurs over much of the day side of the Red Planet, where auroras are very hard to see.

Auroras flare up when energetic particles plunge into a planet’s atmosphere, bombarding gases and making them glow. While electrons generally cause this natural phenomenon, sometime protons can elicit the same response, although it’s more rare. Now, the MAVEN team has learned that protons were doing at Mars the same thing as electrons usually do at Earth—create aurora. This is especially true when the Sun ejects a particularly strong pulse of protons, which are hydrogen atoms stripped of their lone electrons by intense heat. The Sun ejects protons at speeds up to two million miles per hour (more than 3 million kilometers per hour) in an erratic flow called the solar wind.

The MAVEN (Mars Atmosphere and Volatile Evolution mission) team was studying Mars’ atmosphere with the Imaging UltraViolet Spectrograph (IUVS), and observed that on occasion, the ultraviolet light coming from hydrogen gas in Mars’ upper atmosphere would mysteriously brighten for a few hours. They then noticed that the brightening events occurred when another MAVEN instrument, the Solar Wind Ion Analyzer (SWIA), measured enhanced solar wind protons.

March 31st, 2017

NASA orbiter shows Mars lost 90 per cent of its CO2 to space

It vanished into thin air. Around 90 per cent of the Red Planet’s atmosphere was probably lost to space over just a few hundred million years, according to a key measurement from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft.

Today Mars is a freezing, arid desert with an atmosphere 1 per cent as dense as Earth’s and its water mostly locked up in polar ice caps.

But most planetary scientists think it was not always so. Certain Mars soils contain minerals that on Earth are produced in the presence of water, and some Martian features seem to point towards ancient lakebeds and even fast-flowing rivers. To have retained this liquid water, the planet’s carbon dioxide-dominated atmosphere must once have been much thicker to limit surface evaporation.

MAVEN has been orbiting Mars since 2014 on a quest to find out where all that CO2 went. It could have gone into the ice caps, into the rocks as carbonate minerals or it could have been lost to space.

March 2nd, 2017

NASA Orbiter Steers Clear of Mars Moon Phobos

Illustration of a previous close encounter between MAVEN and Phobos – Image: NASA, CU/LASP

Illustration of a previous close encounter between MAVEN and Phobos – Image: NASA, CU/LASP

NASA’s MAVEN spacecraft performed a previously unscheduled maneuver this week to avoid a collision in the near future with Mars’ moon Phobos.

The Mars Atmosphere and VolatileEvolutioN (MAVEN)spacecraft has been orbiting Mars for just over two years, studying the Red Planet’s upper atmosphere, ionosphere and interactions with the sun and solar wind. On Tuesday the spacecraft carried out a rocket motor burn that boosted its velocity by 0.4 meters per second (less than 1 mile per hour). Although a small correction, it was enough that — projected to one week later when the collision would otherwise have occurred — MAVEN would miss the lumpy, crater-filled moon by about 2.5 minutes.

This is the first collision avoidance maneuver that the MAVEN spacecraft has performed at Mars to steer clear of Phobos. The orbits of both MAVEN and Phobos are known well enough that this timing difference ensures that they will not collide.

October 18th, 2016

MAVEN Gives Unprecedented Ultraviolet View of Mars

New global images of Mars from the MAVEN mission show the ultraviolet glow from the Martian atmosphere in unprecedented detail, revealing dynamic, previously invisible behavior. They include the first images of “nightglow” that can be used to show how winds circulate at high altitudes. Additionally, dayside ultraviolet imagery from the spacecraft shows how ozone amounts change over the seasons and how afternoon clouds form over giant Martian volcanoes. The images were taken by the MAVEN Imaging UltraViolet Spectrograph (IUVS).

“MAVEN obtained hundreds of such images in recent months, giving some of the best high-resolution ultraviolet coverage of Mars ever obtained,” said Nick Schneider of the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. Schneider is presenting these results Oct. 19 at the American Astronomical Society Division for Planetary Sciences meeting in Pasadena, California.

October 4th, 2016

NASA’S MAVEN Spacecraft Celebrates One Mars Year of Science NASA

MAVEN’s Imaging UltraViolet Spectrograph obtained this image of Mars on July 13, 2016, when the planet appeared nearly full when viewed from the highest altitudes in the MAVEN orbit. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. The ultraviolet (UV) view gives several new perspectives on Mars. Valles Marineris, a two-thousand-mile canyon system, appears prominently across the middle of the image as a blue gash. The deep canyon appears blue due to the scattering of ultraviolet light by the atmosphere, so strong that we cannot make out the bottom of the canyon. The greenish cast of the planet as a whole is a combination of the reflection of the surface plus the atmospheric scattering. The three tall Tharsis volcanoes appear near the left edge, dotted by white clouds forming as the winds flow over them. Bright white polar caps appear at both poles, typical for this season, in which there is a transition from southern-hemisphere winter to summer. The magenta-colored region visible at the south pole shows where ozone is absorbing ultraviolet light — the same property of ozone that protects life on Earth from harmful UV radiation. While ozone tends to be destroyed by chemical processes in the winter on Earth, different atmospheric chemistry at Mars caused it to build up in the winter there. A hint of ozone is also visible near the north pole; more will accumulate there as winter is coming. IUVS obtains images of Mars every orbit when the sunlit portion of the planet is visible from high altitude.
Credits: NASA/Goddard/University of Colorado/LASP

Today, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) mission completed one Mars year of science observations. One Mars year is just under two Earth years.

MAVEN launched on Nov. 18, 2013, and went into orbit around Mars on Sept. 21, 2014. During its time at Mars, MAVEN has answered many questions about the Red Planet.

March 10th, 2016

Close comet flyby threw Mars’ magnetic field into chaos NASA

The close encounter between comet Siding Spring and Mars flooded the planet with an invisible tide of charged particles from the comet’s coma. The dense inner coma reached the surface of the planet, or nearly so. The comet’s powerful magnetic field temporarily merged with, and overwhelmed, the planet’s weak field, as shown in this artist’s depiction. Illustration credits: NASA/Goddard.

Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet. To protect sensitive equipment aboard MAVEN from possible harm, some instruments were turned off during the flyby; the same was done for other Mars orbiters. But a few instruments, including MAVEN’s magnetometer, remained on, conducting observations from a front-row seat during the comet’s remarkably close flyby.
The one-of-a-kind opportunity gave scientists an intimate view of the havoc that the comet’s passing wreaked on the magnetic environment, or magnetosphere, around Mars. The effect was temporary but profound.

“Comet Siding Spring plunged the magnetic field around Mars into chaos,” said Jared Espley, a MAVEN science team member at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”

March 2nd, 2016

MAVEN Observes Mars Moon Phobos in the Mid- and Far-Ultraviolet NASA

Phobos as observed by MAVEN’s Imaging Ultraviolet Spectrograph. Orange shows mid-ultraviolet (MUV) sunlight reflected from the surface of Phobos, exposing the moon’s irregular shape and many craters. Blue shows far ultraviolet light detected at 121.6 nm, which is scattered off of hydrogen gas in the extended upper atmosphere of Mars. Phobos, observed here at a range of 300km, blocks this light, eclipsing the ultraviolet sky.
Credits: CU/LASP and NASA

NASA scientists are closer to solving the mystery of how Mars’ moon Phobos formed.

In late November and early December 2015, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission made a series of close approaches to the Martian moon Phobos, collecting data from within 300 miles (500 kilometers) of the moon.

Among the data returned were spectral images of Phobos in the ultraviolet. The images will allow MAVEN scientists to better assess the composition of this enigmatic object, whose origin is unknown.