Massive Mars Dust Storm Won’t Stop NASA’s Next Lander

The global dust storm currently raging on Mars shouldn’t disrupt the touchdown of NASA’s InSight lander this fall, agency officials said.

The planet-encircling storm is expected to subside by the time InSight arrives in November. But it won’t be a disaster for the new lander if the storm still swirls or if another one takes its place, officials said.

Rob Grover, leader of Insight’s Entry, Descent and Landing (EDL) team at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, told [NASA’s InSight Mars Lander: Here’s 10 Surprising Facts]

Even if the storm subsides as expected, a dusty haze will likely still hang in the Martian atmosphere when InSight arrives, said Richard Zurek, chief scientist of the Mars Program Office at JPL. That haze could affect how InSight’s science instruments function, because it will prevent some sunlight from reaching the solar-powered lander. But touchdown should be fine, Zurek added.

Not a shock

Martian dust storms can pop up suddenly and last for weeks or even months. The current tempest contains several smaller, active dust storms and appears to have been triggered by a single local storm first observed at the end of May.

Previous NASA Mars missions have dealt with such storms or observed them up close.

When NASA’s Mariner 9 spacecraft reached Mars in November 1971, for example, it caught sight of a global dust storm that had been raging for several weeks. This was the second major storm of the year, researchers knew, because they had observed the first from Earth before the spacecraft’s Red Planet arrival. The Mariner 9 storm was huge and dramatic; it covered the entire Martian surface in dust, except the peaks of the tallest volcanoes.

Another major dust storm, comparable in size to the current one, raged across Mars when NASA’s Viking mission arrived in 1976. That, too, was the second global storm that year.

Landing in a storm

If the storm lasts for its maximum estimated duration, it should falL off just before InSight arrives, NASA officials have said. But it will likely leave traces in the Red Planet’s air regardless.

From an EDL standpoint, the biggest impact of the storm will be the way air is distributed in the Martian atmosphere, Grover said. During storms, dust heats the upper atmosphere, while the shaded lower atmosphere gets cooler. From the beginning of the InSight project, atmospheric modelers have provided a range of conditions that the lander might fly through during its critical EDL sequence, including dust storms, Grover said.

InSight will deploy a big parachute to slow down in the Martian atmosphere, then wrap up its descent by firing retro-rockets when close to the ground. A dusty atmosphere might require the parachute to be deployed as much as 0.9 miles (1.5 kilometers) lower than it would be in clear skies, Grover said. That would shave about 20 seconds off the 6.5-minute entry-to-landing timeline, he added.

When the parachute deploys, the suddenly slowed spacecraft will jerk backward, feeling what Grover called a “snatch force.” The goal is to keep that force under 15,000 lbs. (6,800 kilograms), he said. The amount of force is related to atmospheric density, which changes during or after a dust storm.

“We can tune how we’re actually going to fly on landing day,” Grover said. Minor changes could be sent to the spacecraft as soon as 2 hours before the landing, allowing the team to make adjustments based on the weather closer to the planet.

InSight also boasts an extra 0.2 inches (0.5 centimeters) of thermal protection on its heat shield, because a dust-thickened atmosphere generates more heat than clear skies do.

Like previous NASA Mars missions, InSight — which launched in early May — will use radar to assist with its landing. Ten minutes before it enters the atmosphere, the spacecraft will link with Earth to update its position and velocity based on radar observations. As it plunges into the (likely dusty) Martian atmosphere, InSight will rely on an inertial measurement unit (IMU), which uses an accelerometer and gyros to figure out the craft’s position as it flies through the atmosphere. The radar will then provide critical updates on the spacecraft’s altitude so that the lander knows where it is in relation to the ground.

“We can’t land successfully without the radar,” Grover said. This radar is capable of seeing through dust, allowing the mission to land safely even in a storm, he stressed.

Things will be different, by the way, for NASA’s Mars 2020 rover mission, which will rely on Terrain-Relative Navigation. Mars 2020 will use a camera to create a map of the landing site, comparing the landmarks in the images to those found on the craft’s onboard map. This new technology will allow the spacecraft to shift its direction to avoid landing on dangerous objects. Grover said that a dust storm would impede the device, making a safe landing a challenge. But, unlike InSight, Mars 2020 won’t arrive during dust-storm season.

On the ground
InSight — which is short forU —robot in depthThe stationary lander will help researchers map out the Red Planet’s interior by precisely measuring heat flow and analyzing tiny “marsquakes.”

Dust could affect InSight’s scientific work, because the lander relies on solar panels to power its instruments.

A new dust storm could affect “the deployment of instruments from this solar-powered platform,” Zurek said. The dust could also cover the panels after the instruments have been deployed.

“That’s the main worry, that the dust storm is going to cover your solar panels,” said Matt Siegler, a research scientist at the Planetary Science Institute in Arizona who works on InSight’s heat-probe instrument.

The problem is similar to the one NASA’s solar-powered Opportunity rover currently faces. The nearly 15-year old Opportunity has hunkered down during the global storm, likely entering a “low-power fault mode,” in which all subsystems other than the mission clock turn off. The mission clock is programmed to wake the computer to check its power levels.

The massive dust storm has blotted out the sun, keeping Opportunity from charging its batteries. The batteries don’t just run the instruments; they also keep the rover warm during the cold Martian nights. Without such heat, big problems can arise.

“Some soldered joint will get too cold and split, and then your computer dies,” Siegler said.

The dust storm itself could help keep Opportunity warm, because dust can trap heat close to the planet’s surface. Indeed, calculations by the Opportunity team suggest that temperatures won’t get cold enoughin the immediate future to freeze that rover out, NASA officials said last month.

When InSight lands, it should have enough power to keep its instruments warm for some time, Zurek said. Once the storm passes and the skies clear somewhat, the spacecraft will be able to begin its mission exploring the Martian interior.

In the meantime, scientists will keep their eyes on the enormous weather event.

“The current storm is still developing, and atmospheric scientists here at JPL are continuing to observe it,” Grover said.

Scientists Discover Earth’s Youngest Banded Iron Formation In Western China

The banded iron formation, located in western China, has been conclusively dated as Cambrian in age. Approximately 527 million years old, this formation is young by comparison to the majority of discoveries to date. The deposition of banded iron formations, which began approximately 3.8 billion years ago, had long been thought to terminate before the beginning of the Cambrian Period at 540 million years ago.

“This is critical, as it is the first observation of a Precambrian-like banded iron formation that is Early Cambrian in age. This offers the most conclusive evidence for the presence of widespread iron-rich conditions at a time, confirming what has recently been suggested from geochemical proxies,” said Kurt Konhauser, professor in the Department of Earth and Atmospheric Sciences and co-author. Konhauser supervised the research that was led by Zhiquan Li, a PhD candidate from Beijing while on exchange at UAlberta.

The Early Cambrian is known for the rise of animals, so the level of oxygen in seawater should have been closer to near modern levels. “This is important as the availability of oxygen has long been thought to be a handbrake on the evolution of complex life, and one that should have been alleviated by the Early Cambrian,” says Leslie Robbins, a PhD candidate in Konhauser’s lab and a co-author on the paper.

The researchers compared the geological characteristics and geochemistry to ancient and modern samples to find an analogue for their deposition. The team relied on the use of rare earth element patterns to demonstrate that the deposit formed in, or near, a chemocline in a stratified iron-rich basin.

“Future studies will aim to quantify the full extent of these Cambrian banded iron formations in China and whether similar deposits can be found elsewhere,” says Kurt Konhauser.

Dominican Republic: Tropical Storm Beryl Leaves Thousands Displaced, Without Water, Power

The capital of Santo Domingo was left without electricity from the first major storm of the 2018 Atlantic hurricane season.

Heavy rains from Tropical Storm Beryl have left at least 8,000 people displaced, and 19 villages without communication in the Dominican Republic, the Emergency Operations Center said.

Thousands are left without drinking water, as the storm has knocked 75 aqueducts out of service.

The capital of Santo Domingo was left without electricity from the first major storm of the 2018 Atlantic hurricane season.

The Center still has 22 provinces on alert for flooding and landslides.

In San Cristobal province, 700 homes were flooded and two schools collapsed.

A member of National Congress, Ito Bisono, tweeted pictures of a recently opened hospital flooded.

“A country with a supposedly growing economy cannot have hospitals where it rains more inside than outside,” Bisono tweeted.

Tropical Storm Beryl was earlier a category 1 hurricane, but was then downgraded to a tropical storm. In spite of having lost its earlier heavy wind power, strong rains pose an equally dangerous threat.

Rocky Planet Neighbor Looks Familiar, But Is Not Earth’s Twin

Last autumn, the world was excited by the discovery of an exoplanet called Ross 128 b, which is just 11 light years away from Earth. New work from a team led by Diogo Souto of Brazil’s Observatório Nacional and including Carnegie’s Johanna Teske has for the first time determined detailed chemical abundances of the planet’s host star, Ross 128.

Understanding which elements are present in a star in what abundances can help researchers estimate the makeup of the exoplanets that orbit them, which can help predict how similar the planets are to the Earth.

“Until recently, it was difficult to obtain detailed chemical abundances for this kind of star,” said lead author Souto, who developed a technique to make these measurements last year.

Like the exoplanet’s host star Ross 128, about 70 percent of all stars in the Milky Way are red dwarfs, which are much cooler and smaller than our Sun. Based on the results from large planet-search surveys, astronomers estimate that many of these red dwarf stars host at least one exoplanet. Several planetary systems around red dwarfs have been newsmakers in recent years, including Proxima b, a planet which orbits the nearest star to our own Sun, Proxima Centauri, and the seven planets of TRAPPIST-1, which itself is not much larger in size than our Solar System’s Jupiter.

Using the Sloan Digital Sky Survey’s APOGEE spectroscopic instrument, the team measured the star’s near-infrared light to derive abundances of carbon, oxygen, magnesium, aluminum, potassium, calcium, titanium, and iron.

“The ability of APOGEE to measure near-infrared light, where Ross 128 is brightest, was key for this study,” Teske said. “It allowed us to address some fundamental questions about Ross 128 b’s `Earth-like-ness’,” Teske said.

When stars are young, they are surrounded by a disk of rotating gas and dust from which rocky planets accrete. The star’s chemistry can influence the contents of the disk, as well as the resulting planet’s mineralogy and interior structure. For example, the amount of magnesium, iron, and silicon in a planet will control the mass ratio of its internal core and mantle layers.

The team determined that Ross 128 has iron levels similar to our Sun. Although they were not able to measure its abundance of silicon, the ratio of iron to magnesium in the star indicates that the core of its planet, Ross 128 b, should be larger than Earth’s.

Because they knew Ross 128 b’s minimum mass, and stellar abundances, the team was also able to estimate a range for the planet’s radius, which is not possible to measure directly due to the way the planet’s orbit is oriented around the star.

Knowing a planet’s mass and radius is important to understanding what it’s made of, because these two measurements can be used to calculate its bulk density. What’s more, when quantifying planets in this way, astronomers have realized that planets with radii greater than about 1.7 times Earth’s are likely surrounded by a gassy envelope, like Neptune, and those with smaller radii are likely to be more-rocky, as is our own home planet.

The estimated radius of Ross 128 b indicates that it should be rocky.

Lastly, by measuring the temperature of Ross 128 and estimating the radius of the planet the team was able to determine how much of the host star’s light should be reflecting off the surface of Ross 128 b, revealing that our second-closest rocky neighbor likely has a temperate climate.

“It’s exciting what we can learn about another planet by determining what the light from its host star tells us about the system’s chemistry,” Souto said. “Although Ross 128 b is not Earth’s twin, and there is still much we don’t know about its potential geologic activity, we were able to strengthen the argument that it’s a temperate planet that could potentially have liquid water on its surface.”

Oxygen Levels On Early Earth Rose, Fell Several Times Before Great Oxidation Event

Earth’s oxygen levels rose and fell more than once hundreds of millions of years before the planetwide success of the Great Oxidation Event about 2.4 billion years ago, new research from the University of Washington shows.

The evidence comes from a new study that indicates a second and much earlier “whiff” of oxygen in Earth’s distant past — in the atmosphere and on the surface of a large stretch of ocean — showing that the oxygenation of the Earth was a complex process of repeated trying and failing over a vast stretch of time.

The finding also may have implications in the search for life beyond Earth. Coming years will bring powerful new ground- and space-based telescopes able to analyze the atmospheres of distant planets. This work could help keep astronomers from unduly ruling out “false negatives,” or inhabited planets that may not at first appear to be so due to undetectable oxygen levels.

“The production and destruction of oxygen in the ocean and atmosphere over time was a war with no evidence of a clear winner, until the Great Oxidation Event,” said Matt Koehler, a UW doctoral student in Earth and space sciences and lead author of a new paper published the week of July 9 in the Proceedings of the National Academy of Sciences.

“These transient oxygenation events were battles in the war, when the balance tipped more in favor of oxygenation.”

In 2007, co-author Roger Buick, UW professor of Earth and space sciences, was part of an international team of scientists that found evidence of an episode — a “whiff” — of oxygen some 50 million to 100 million years before the Great Oxidation Event. This they learned by drilling deep into sedimentary rock of the Mount McRae Shale in Western Australia and analyzing the samples for the trace metals molybdenum and rhenium, accumulation of which is dependent on oxygen in the environment.

Now, a team led by Koehler has confirmed a second such appearance of oxygen in Earth’s past, this time roughly 150 million years earlier — or about 2.66 billion years ago — and lasting for less than 50 million years. For this work they used two different proxies for oxygen — nitrogen isotopes and the element selenium — substances that, each in its way, also tell of the presence of oxygen.

“What we have in this paper is another detection, at high resolution, of a transient whiff of oxygen,” said Koehler. “Nitrogen isotopes tell a story about oxygenation of the surface ocean, and this oxygenation spans hundreds of kilometers across a marine basin and lasts for somewhere less than 50 million years.”

The team analyzed drill samples taken by Buick in 2012 at another site in the northwestern part of Western Australia called the Jeerinah Formation.

The researchers drilled two cores about 300 kilometers apart but through the same sedimentary rocks — one core samples sediments deposited in shallower waters, and the other samples sediments from deeper waters. Analyzing successive layers in the rocks years shows, Buick said, a “stepwise” change in nitrogen isotopes “and then back again to zero. This can only be interpreted as meaning that there is oxygen in the environment. It’s really cool — and it’s sudden.”

The nitrogen isotopes reveal the activity of certain marine microorganisms that use oxygen to form nitrate, and other microorganisms that use this nitrate for energy. The data collected from nitrogen isotopes sample the surface of the ocean, while selenium suggests oxygen in the air of ancient Earth. Koehler said the deep ocean was likely anoxic, or without oxygen, at the time.

The team found plentiful selenium in the shallow hole only, meaning that it came from the nearby land, not making it to deeper water. Selenium is held in sulfur minerals on land; higher atmospheric oxygen would cause more selenium to be leached from the land through oxidative weathering — “the rusting of rocks,” Buick said — and transported to sea.

“That selenium then accumulates in ocean sediments,” Koehler said. “So when we measure a spike in selenium abundances in ocean sediments, it could mean there was a temporary increase in atmospheric oxygen.”

The finding, Buick and Koehler said, also has relevance for detecting life on exoplanets, or those beyond the solar system.

“One of the strongest atmospheric biosignatures is thought to be oxygen, but this study confirms that during a planet’s transition to becoming permanently oxygenated, its surface environments may be oxic for intervals of only a few million years and then slip back into anoxia,” Buick said.

“So, if you fail to detect oxygen in a planet’s atmosphere, that doesn’t mean that the planet is uninhabited or even that it lacks photosynthetic life. Merely that it hasn’t built up enough sources of oxygen to overwhelm the ‘sinks’ for any longer than a short interval.

“In other words, lack of oxygen can easily be a ‘false negative’ for life.”

Koehler added: “You could be looking at a planet and not see any oxygen — but it could be teeming with microbial life.”

Fragment Of Impacting Asteroid Recovered In Botswana

On Saturday, June 23, 2018, a team of experts from Botswana, South Africa, Finland and the United States of America recovered a fresh meteorite in Botswana´s Central Kalahari Game Reserve (CKGR).

The meteorite is one of the fragments of asteroid 2018 LA which collided with Earth on June 2, 2018 and turned into a meteor fireball that detonated over Botswana a few seconds after entering the atmosphere. The incident was witnessed by a number of spectators in Botswana and neighbouring countries and was captured on numerous security cameras.

Asteroid 2018 LA was detected in space eight hours before hitting Earth. It was detected by the Catalina Sky Survey, operated by the University of Arizona and sponsored by NASA as part of its Planetary Defence mission. This is the third time in history that an asteroid inbound to hit Earth was detected early and only the second time that fragments were recovered. After disruption, the asteroid fragments were blown by the wind while falling down, scattering over a wide area. Calculations of the landing area were done independently by a US-based group headed by Peter Jenniskens, a subject expert of the NASA-sponsored SETI Institute in California, as well as Esko Lyytinen and Jarmo Moilanen of the Finnish Fireball Network (FFN).

The first meteorite was found after five days of walking and scouring around by a team of geoscientists from Botswana International University of Science and Technology (BUIST), Botswana Geoscience Institute (BGI) and University of Botswana´s Okavango Research Institute (ORI). The Department of Wildlife and National Parks granted access and deployed park rangers for protection and participation in the search. The importance of the find is two-fold: It has enormous scientific value and it allows to better calibrate the so-called “Earth Defense” against impacting asteroids.

Jenniskens, who traveled to Botswana to assist in the search, teamed up with Oliver Moses (from ORI), to gather security surveillance videos in Rakops and Maun, to get better constraints on the position and altitude of the fireball´s explosion. Professor Alexander Proyer, from BIUST, led the joint expedition while Mohutsiwa Gabadirwe, BGI senior curator, coordinated access to the protected fall area in the game reserve. Professor Roger Gibson, Head of School at the School of Geosciences at the University of the Witwatersrand in Johannesburg, South Africa, also assisted in locating the fall area. The meteorite was eventually spotted by BIUST geologist Lesedi Seitshiro. The search for more fragments of the meteorite continues. Dr Fulvio Franchi of BIUST, is leading the follow-up search team joined by Tomas Kohout of the FFN and the University of Helsinki.

Meteorites are protected under Botswana law and samples will be curated by the Botswana National Museum and investigated further by a research consortium of scientists coordinated by Botswana Geoscience Institute (BGI).

Tropical Depression Three Forms Off Carolina Coast, Likely to Become Tropical Storm Chris

Tropical Depression Three has formed several hundred miles southeast of North Carolina and will become Tropical Storm Chris this weekend.

Infrared satellite imagery indicates showers and thunderstorms are gradually becoming more numerous and consolidating a few hundred miles southeast of Wilmington, North Carolina, enough so that the National Hurricane Center has upgraded the system to a tropical depression.

The National Hurricane Center says intensification is likely over the next few days, and it could become a hurricane on Tuesday or Wednesday.

Several hurricane hunter flights have been scheduled to see how well organized and how strong the system is. The first of these flights is scheduled for Saturday morning.

Stalling Out
The rest of the forecast at this time is tricky.

Here’s what the National Hurricane Center has come up with followed by our forecast reasoning.

This system isn’t going to move much over the next few days. Stalled tropical cyclones, such as Debby in 2012, are notoriously difficult to forecast.

Tropical Depression Three is too far south to be grabbed by the southward dip in the jet-stream currently bringing heat relief to the Northeast.

When that jet-stream dip goes by this weekend, it will be replaced by another expanding heat dome of high pressure aloft building into the Midwest and East.

This new heat dome will trap the depression near or off the Carolina coast into early next week.

Exactly where this system stalls remains uncertain and will hold the key to some impacts.

If it stalls too far off the coast, the only impacts at the coast from southeast Virginia to the Carolinas may be building surf, rip currents, some coastal flooding at high tide, and occasional showers this weekend into early next week.

If it stalls closer to the coast, some areas may experience heavy rainfall and stronger winds.

Then there’s the intensity forecast.

A stalled tropical system over the Gulf Stream, where surface water temperatures are above average, will likely allow this system to become a hurricane, assuming wind shear remains low and dry air doesn’t impact the system. But, if this system remains too stationary, it could upwell colder waters and cause itself to weaken.

By mid-late next week, another southward plunge of the jet stream is expected to grab this system and send it into the north Atlantic Ocean.