February 21st, 2022

We’re Not Prepared for Contamination Between Worlds

Illustration: Angelica Alzona

Space agencies across the world have long been aware of the risks of biological contamination, with planetary protection protocols already being established back in the 1960s. These rules have been updated and tweaked ever since, based on the new endeavors at hand. Some of the rules are: everything should be assembled in sterilized clean rooms; every spacecraft should include an inventory listing all organic matter making it on the trip; the total bioburden—the surface presence of microorganisms—should be below certain thresholds according to the category of the mission; and so forth.

Just in 2020, NASA updated its planetary protection policy for the Moon and Mars. This is a big step because, while exploring Mars was basically prohibited by the old contamination protocol, now the reform supports a human mission to Mars and gives guidelines on how to do so safely.

January 17th, 2022

Earth and Mars were formed from inner solar system material

The four terrestrial planets: Mercury, Venus, Earth and Mars. Credit: NASA/Lunar and Planetary Institute

Earth and Mars were formed from material that largely originated in the inner solar system; only a few percent of the building blocks of these two planets originated beyond Jupiter’s orbit. A group of researchers led by the University of Münster (Germany) report these findings today in the journal Science Advances. They present the most comprehensive comparison to date of the isotopic composition of Earth, Mars and pristine building material from the inner and outer solar system. Some of this material is today still found largely unaltered in meteorites. The results of the study have far-reaching consequences for our understanding of the process that formed the planets Mercury, Venus, Earth, and Mars. The theory postulating that the four rocky planets grew to their present size by accumulating millimeter-sized dust pebbles from the outer solar system is not tenable.

Approximately 4.6 billion years ago, in the early days of our solar system, a disk of dust and gasses orbited the young sun. Two theories describe how, in the course of millions of years, the inner rocky planets formed from this original building material. According to the older theory, the dust in the inner solar system agglomerated to ever larger chunks gradually reaching approximately the size of our moon. Collisions of these planetary embryos finally produced the inner planets Mercury, Venus, Earth and Mars. A newer theory, however, prefers a different growth process: Millimeter-sized dust “pebbles” migrated from the outer solar system towards the sun. On their way, they were accreted onto the planetary embryos of the inner solar system, and step by step, enlarged them to their present size.

January 13th, 2022

Study nixes Mars life in meteorite found in Antarctica

The meteorite labeled ALH84001 sits in a chamber at a Johnson Space Center lab in Houston, Aug. 7, 1996. Scientists say they’ve confirmed the meteorite from Mars contains no evidence of ancient Martian life. The rock caused a splash 25 years ago when a NASA-led team announced that its organic compounds may have been left by living creatures, however primitive. Researchers chipped away at that theory over the decades. A team of scientists led by Andrew Steele of the Carnegie Institution published their findings Thursday, Jan. 13, 2022. (AP Photo/David J. Phillip)

A 4 billion-year-old meteorite from Mars that caused a splash here on Earth decades ago contains no evidence of ancient, primitive Martian life after all, scientists reported Thursday.

In 1996, a NASA-led team announced that organic compounds in the rock appeared to have been left by living creatures. Other scientists were skeptical and researchers chipped away at that premise over the decades, most recently by a team led by the Carnegie Institution for Science’s Andrew Steele.

Tiny samples from the meteorite show the carbon-rich compounds are actually the result of water — most likely salty, or briny, water — flowing over the rock for a prolonged period, Steele said. The findings appear in the journal Science.

During Mars’ wet and early past, at least two impacts occurred near the rock, heating the planet’s surrounding surface, before a third impact bounced it off the red planet and into space millions of years ago. The 4-pound (2-kilogram) rock was found in Antarctica in 1984.

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.

June 17th, 2019

NASA’s MRO Snaps ‘Black-And-Blue’ Impact Crater on Mars

NASA’s Mars Reconnaissance Orbiter (MRO) snapped an image of a “black-and-blue” impact crater on the Red Planet. (Photo Credit: Nahúm Méndez Chazarra, NASA / JPL / University of Arizona)

Mars recently received a hard “punch” when a small space rock hurtled into the Red Planet’s surface and created a new impact crater that looks like a black-and-blue bruise.

The impact crater, which is estimated to be 49 feet to 53 feet in width, was captured in a new image from NASA’s Mars Reconnaissance Orbiter (MRO), reported. The MRO, which has been analyzing Mars for more than 13 years with its High Resolution Imaging Science Experiment (HiRISE) camera and its lower-resolution Context Camera (CTX), snapped a HiRISE color image in April and it was shared by NASA on June 6. Researchers say the “black-and-blue” Mars crater could have formed between September 2016 and February 2019.

January 23rd, 2019

NASA discovers fresh ‘blast pattern’ on Mars

Sometime between July and September of 2018, a rock smacked into Mars and left an impressive mark near the planet’s south pole.

NASA’s Mars Reconnaissance Orbiter (MRO) snapped a view of the resulting impact crater and the explosive signature it left on the icy landscape.

“It’s notable because it occurred in the seasonal southern ice cap, and has apparently punched through it, creating a two-toned blast pattern,” NASA planetary scientist Ross Beyer said of the image released on Tuesday.

Impact craters result when a meteoroid or other space-faring rock collides with Mars.

December 6th, 2018

Meteorites from Mars Suffer a Velocity Boost Due to Material Pileup

A cartoon on the generation of Martian meteorites. – Tokyo Institute of Technology

One hundred and ninety-eight meteorites from Mars have been discovered on Earth as of Sep., 2017. Hypervelocity impacts on Mars have been a widely accepted mechanism that launches Martian rocks into the space. Petrographic analyses of the Martian meteorites have shown that they suffer relatively low peak pressure ranging from 30 to 50 GPa during impact ejection events. In contrast, shock physics tells us that a stronger shock compression higher than 50 GPa is required to accelerate materials up to the escape velocity of Mars (5 km/s). This contradiction between petrology and shock physics was the outstanding problem regarding the Martian meteorites’ launch.

he new discovery of late-stage acceleration has a wide range of implications not only for the Martian meteorites’ launch, but also for material exchange amongst planetary bodies (See Figure 1). Since microbes may survive the relatively weak shock compression, the late-stage acceleration could provide us with new insight into (Litho-)Panspermia. The researchers are planning to do a series of hypervelocity impact experiments to validate the numerically discovered new mechanism using a two-stage light gas gun installed at the Planetary Exploration Research Center, Chiba Institute of Technology, Japan.

April 4th, 2017

Mars’ Trojans Show Remains of Ancient Planetoid

The paths traced by the known Martian Trojans around L4 or L5 (crosses) relative to Mars (red disk) and the Sun (yellow disk). The dotted circle indicates the average Sun-Mars distance. Right: Enlargement of inset (dashed rectangle) showing the paths of the 8 L5 Trojans: 1998 VF31 (marked as

The paths traced by the known Martian Trojans around L4 or L5 (crosses) relative to Mars (red disk) and the Sun (yellow disk). The dotted circle indicates the average Sun-Mars distance. Right: Enlargement of inset (dashed rectangle) showing the paths of the 8 L5 Trojans: 1998 VF31 (marked as “VF31” – blue), Eureka (red) and the 6 objects identified as family members (amber). The filled disks indicate the relative sizes of the asteroids. Eureka, the largest member, is about 2 km across. Figure credit: Apostolos Christou (E-mail:

Trojan asteroids are a fascinating thing. Whereas the most widely known are those that orbit Jupiter (around its L4 and L5 Lagrange Points), Venus, Earth, Mars, Uranus and Neptune have populations of these asteroids as well. Naturally, these rocky objects are a focal point for a lot of scientific research, since they can tell us much about the formation and early history of the Solar System.

And now, thanks to an international team of astronomers, it has been determined that the Trojan asteroids that orbit Mars are likely the remains of a mini-planet that was destroyed by a collision billions of years ago. Their findings are detailed in a paper that will be published in The Monthly Notices of the Royal Astronomical Society later this month.

For the sake of their study, the team – which was led by Galin Borisov and Apostolos Christou of the Armagh Observatory and Planetarium in Northern Ireland, examined the composition of Marian Trojans. This consisted of using spectral data obtained by the XSHOOTER spectrograph on the Very Large Telescope (VLT) and photometric data from the National Astronomical Observatory‘s two-meter telescope, and the William Herschel Telescope.

November 3rd, 2016

Egg Rock: Lessons from the iron meteorite Curiosity found on Mars

The dark, smooth-surfaced rock at the center of this Oct. 30, 2016, image from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover was examined with laser pulses and confirmed to be an iron-nickel meteorite. It is about the size of a golf ball. Credit: NASA/JPL-Caltech/MSSS

The dark, smooth-surfaced rock at the center of this Oct. 30, 2016, image from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover was examined with laser pulses and confirmed to be an iron-nickel meteorite. It is about the size of a golf ball. Credit: NASA/JPL-Caltech/MSSS

It’s been more than four years since NASA’s Curiosity rover landed on Mars, enabling researchers to study the shape and composition of the planet’s landscape in a mission that had originally been planned to last less than two years. Even as the rover’s instruments begin to show signs of wear and tear, however, scientists are still making discoveries.

For the first time on Mars, researchers used a spectrometer to zap an object the size of a golfball with a laser this week to confirm that it is an iron-nickel meteorite that fell to the planet’s surface, according to NASA and the Jet Propulsion Laboratory. Although such objects are common on Earth and to be expected on the Red Planet as well, studying them in tandem with what we already know about the planet’s atmosphere could reveal a wealth of new information about the history of the solar system.

Horton Newsom, a researcher from the University of New Mexico, Albuquerque, said the object, known as Egg Rock, could carry within its core information that differs from asteroids currently being studied.

August 7th, 2015

3D-Printed Mars Meteorite

Back in 2009, scientists detected an odd-shaped rock by the Mars Exploration Rover Opportunity’s panorama camera. NASA’s Jet Propulsion Lab (JPL) team spotted the rock, now called Block Island, in the images downlinked to Earth after it had driven past the rock. The rover backtracked some 820 feet to study Block Island closer, eventually touching the rock with its robotic arm. The image showed a rock approximately 2 feet in length and half that in height, with a metallic bluish tint that distinguished it from other rocks in the area. Upon further analysis scientists discovered that Block Island was a meteorite comprised of iron and nickel. A portion of Block Island’s surface indicated exposure when a meteorite is abraded, polished, and etched by windblown sand.