Category: Missions (page 1 of 10)

The Surface of Venus Was Thought to Be Stagnant. But This May Not Be True

An oblique radar view of the largest “pack ice” block in the Venus lowlands identified by Byrne et al. (Paul Byrne, based on original NASA/JPL imagery).

The two Earth-sized planets in our solar system have taken wildly different evolutionary routes. The surface of the Earth became a temperate utopia for a liquid water and a myriad of life. But while similar in both size and mass, the surface of the neighboring Venus is hot enough to melt lead.

These differences are the key to understanding the possible outcomes for a rocky planet after it forms out of the dusty disk around a young star. Knowledge of the rocky options is needed to identify the surface environments of extrasolar planets from the limited data we can gleam through our telescopes, and to unpick the properties needed to form a habitable planet. It is a task considered so important that three new Venus missions were approved by NASA and ESA in the last month.

(Read about these missions on Many Worlds here and here)

One such difference between the Earth and Venus is the type of planet surface or, more precisely, the structure of the planet lithosphere that comprises of the crust and uppermost part of the mantle.

The Earth’s lithosphere is broken into mobile chunks that can subduct beneath one another, bunch up to form mountain rages, or pull part. This motion is known as plate tectonics, and it allows material to be cycled between our surface and the hidden mantle deep below our feet. It is a geological process that replenishes nutrients, cools the planet interior, and also forms part of the Earth’s carbon cycle that adjusts the levels of carbon dioxide in our atmosphere to keep our environment temperate. Without this cycling ability, the Earth would not have been able to stay habitable over such a long period.

Venus and the Earth are extremely close in size and mass. Yet, only the Earth developed plate tectonics (ESA).

By contrast, the lithosphere of Venus does not form plates. This prevents carbon from being drawn into the mantle, and any nutrients below the surface are unreachable. Indeed, the surface of Venus has long been thought to be a single piece of immobile, stagnant lid, with no connection at all with the planet interior.

Not only does the lack of geological processes throttle Venus’s environment, the seemingly complete immobility of the lithosphere was extremely annoying.… Read more

Will The Habitable Exoplanet Observatory (HabEx) — Or Something Like It — Emerge As NASA’s Next Great Observatory?

Artist impression of HabEx spacecraft and a deployed starshade 47,000 miles away, with an exoplanet made visible by the starshade’s blocking of stellar light. (NASA)

Some time later this summer, it is predicted, the National Academy of Sciences will release its long-awaited Decadal Survey for astrophysics, which is expected to recommend the science and architecture that NASA should embrace for its next “Great Observatory.”

Many Worlds earlier featured one of the four concepts in the running — LUVOIR or the Large UV/Optical/IR Surveyor.  With a segmented mirror potentially as wide as 50 feet in diameter, it would revolutionize the search for habitable exoplanets and potentially could detect one (or many) distant planets likely to support life.

Proposed as a “Great Observatory” for the 2030s in the tradition of the Hubble Space Telescope and the James Webb Space Telescope (scheduled to launch later this year), LUVOIR would allow for transformative science of not only exoplanets but many other fields of astronomy as well.

Also under serious consideration is the Habitable Exoplanet Observatory, HabEx, which would also bring unprecedented capabilities to the search for life beyond Earth.  Its mirror would be considerably smaller than that proposed for LUVOIR and it would have fewer chances to find an inhabited world.

But it is nonetheless revolutionary in terms of what it potentially can do for exoplanet science and it could come with a second spacecraft that seems to be out of science fiction,  designed to block out starlight so exoplanets nearby can be observed. That 52-meter (or 170-foot) petal-rimmed, light-blocking disc is called a starshade or an occulter, and it would fly 76,600 kilometers (or 47,000 miles) away from the HabEx spacecraft and would work in tandem with the telescope to make those close-in exoplanet observations possible.

While the capabilities of HabEx are fewer compared to LUVOIR and the potential harvest of habitable or inhabited planets is less, HabEx nonetheless would be cutting edge and significantly more capable than the Hubble Space Telescope in nearly every way, while also being less expensive than LUVOIR and requiring less of a technology reach.

Scott Gaudi, an Ohio State University astronomer, was co-chair of the NASA-created team that spent three years studying, engineering and then proposing the HabEx concept. He put the potential choice between HabEx and LUVOIR this way:  “Do you want to take a first step or a first leap?  HabEx is a major step; LUVOIR is a huge leap.”… Read more

And Then There Were Three: ESA Follows NASA in Selecting a Mission to Venus

Artist illustration of the EnVision orbiter at Venus (ESA/VR2Planets/DamiaBouic)

It was quite a week for Venus scientists. Just seven days after NASA announced the selection of two Venus missions, DAVINCI+ and VERITAS, the European Space Agency (ESA) revealed that a third Venus mission had been chosen for the agency’s medium-class mission category.

(See last week’s post here on Many Worlds about DAVINCI+ and VERITAS)

The new mission is named EnVision, and will be ESA’s second Venus mission following Venus Express (2005 – 2014), which investigated the Venusian climate. While EnVision is an orbiter like Venus Express and VERITAS, its focus is the planet’s geological circulation system that links the atmosphere, surface and interior.

In case you are starting to get your Venus missions in a tangle, the set can be broadly divided up as follows:

Venus Express (ESA: 2005 – 2014) and Akatsuki (JAXA: 2015 – current) are both Venus orbiters focussed on the planet’s climate, returning information about the rapidly rotating upper atmosphere and acidic cloud deck of Venus.

DAVINCI+ (NASA: est. 2029 launch) is an orbiter and descending probe that will dive through the Venusian atmosphere to return top-to-bottom data on the planet’s stifling gases.

VERITAS (NASA: est. 2028 launch) is an orbiter focussed on Venus’s surface and the deep interior. VERITAS will bring us global maps in three-dimensions at a resolution of 30m. This will knock the socks off our current images from NASA’s Magellan orbiter (1989 – 1994), which had a resolution of around 200m.

EnVision (ESA: early 2030s) is the mission focused on how these environments are linked together. Equipped with an instrument suite that covers the top of the atmosphere through to below the planet surface, EnVision will probe how the different regions influence one another to create the planet’s internal systems.

“EnVision has a holistic approach,” explained Jörn Helbert who is a member of the EnVision team. “The larger and more complex payload studies Venus from the top of the atmosphere all the way to the subsurface, with a focus on understanding how the coupled system on Venus works.”

Artist illustration of the EnVision spacecraft, reflecting the goal of understanding why Venus and Earth are so different (NASA / JAXA / ISAS / DARTS / Damia Bouic / VR2Planets).

The coupled system is at the heart of how habitability can develop on rocky planets. A major player in the Earth’s environment is the ability to cycle carbon between the atmosphere, surface and planet mantle.… Read more

Return to Hell: NASA Selects Two Missions to Venus to Explore the Pathway to Habitability

Artists’ renderings show the VERITAS spacecraft (left) and DAVINCI+ probe (right) as they arrive at Venus (Lockheed Martin).

For NASA scientists, Venus missions must feel like buses. You wait thirty years for one, and then two come along at once.

Last week, NASA selected two Venus missions for the space agency’s Discovery Program; solar system exploration missions that can tuck under a lower cost cap than candidates for NASA’s New Horizons or Flagship categories. The first of these is DAVINCI+, which is an orbiter equipped with a descending probe that will take a big whiff of Venus’s stifling atmosphere. The second is the VERITAS orbiter that plans to peer through the clouds to scrutinise the Venusian surface.

While Europe and Japan have both visited Venus more recently than NASA (in fact, the Japanese orbiter is still there), there is little doubt that our inner neighbor is dramatically under-explored compared to Mars. But why the past neglect, and why go twice now?

The answer to the first question is perhaps the easiest.

Venus is hell.

The planet is wrapped in a thick atmosphere consisting of carbon dioxide and clouds of sulfuric acid that beat down on the Venusian surface with pressures nearly one hundred times higher than on Earth and create temperatures sufficient to melt lead.

These conditions have made it difficult to follow the usual pattern of planetary exploration from fly-bys and orbiters to landers and rovers. The Venusian surface is so inhospitable that a rover like NASA’s Mars Perseverance would become rover goop. Although recent engineering combined with high-temperature electronics means that the surface is no longer impossible, it does greatly add to the challenge (and therefore cost) of a lander mission.

Professor Stephen Kane, University of California, Riverside.

Hell-scape conditions have also resulted in Venus being overlooked for any astrobiological studies compared to (the still rather nasty but at least you can stand a rover on the surface) Mars. This makes the urgency to explore Venus now particularly surprising. The missions are a quest to understand habitability. The bottom line is that the hell world of Venus is essential to understanding how a planet becomes habitable and to discovering other habitable worlds outside our solar system.

“Imagine you live in a small town full of life,” explains Professor Stephen Kane from the DAVINCI+ team. “The nearest town is the same size and seems it was once identical. But now, it’s burned to the ground with no sign of life.… Read more

China’s Presence in Space Grows and So Do Its Accomplishments

The Chinese Mars lander, with photo taken by the Zhurong rover after it rolled down onto the surface of Mars. (Chinese National Space Administration)

These are heady days for the Chinese space program.

On the heels of a successful 2019 mission to the dark side of the moon and the launch of the core of an ambitious low Earth orbit space station,  the Chinese National Space Administration has done what only NASA has accomplished before — landing a rover on Mars and then setting it into motion on the surface of the planet.

The Zhurong rover, which is named after an ancient fire god in Chinese mythology, rolled off its lander on Saturday and has begun its planned three-month mission.

The rover carries instruments to study the planet’s surface rocks and atmosphere using radar, spectroscopy and a magnetic field detector. It will also look for signs of life, including any subsurface water or ice.

The solar-powered, 530-pound and  six-wheeled robot will be exploring Utopia Planitia in Mars’ northern hemisphere – the general area where NASA’s Viking 2 lander touched down in 1975.  Zhurong will join NASA’s much larger (more than 2,200 pound) Perseverance and Curiosity rovers now operating on Mars.

“We hope we can get a comprehensive covering of Martian topography, landform and environment, and the exploratory data of the radar detecting the Martian subsurface during one Martian year,” said deputy chief commander of the mission, Zhang Yuhua.

“By doing so, our country will have our own abundant and first-hand data about Martian resources,” she said.

The Chinese Mars lander is powered by solar panels and is expected to explore for at least three months.  (Rendering by the Chinese National Space Administration)

While the rover will itself not bring many new technologies and approaches to Mars science, the architecture of the mission is unprecedented.  The Tianwen-1 spacecraft that brought the rover to Mars orbited the planet for more than three months before deploying the lander and rover.  Part of the spacecraft will remain in orbit as a communications hub.

All NASA missions have flown directly to the surface without first going into orbit around Mars.

While the Utopia Planitia region was explored to some extent by Viking 2, much more is known about the region now then was known in the 1970s.

The plains are part of the northern lowlands of Mars, and some theorize that the region was once covered by a great “Northern Ocean.”  Read more

Novel Sights and Sounds on Mars

 

The helicopter Ingenuity has now flown three times on Mars and has proven itself to be a dependable (for now) and potentially ground-breaking addition to Mars science.

Ingenuity, brought to Mars as part of the Perseverance rover landing, took off early Sunday morning on its third and most ambitious Martian mission yet.  The 4-pound helicopter traveled a total of 330 feet laterally, stayed aloft for 80 seconds and reached a maximum speed of about 4.5 mph, handily breaking marks set on its previous two flights.

In the video above, you can see the helicopter taking off on the bottom left, crossing the screen, and then coming back a bit later to land in the same spot.

The “flight was what we planned for, and yet it was nothing short of amazing,” said Dave Lavery, the Ingenuity program executive at NASA Headquarters. “With this flight, we are demonstrating critical capabilities that will enable the addition of an aerial dimension to future Mars missions.”

If this capacity proves to be robust it will clearly have many positive implications for Mars science with successor rotorcraft — allowing scientists to quickly study areas surrounding a rover and to put their discoveries into larger geological contexts.

Ingenuity rover preparing to go airborne. The wings, legs and more were folded up for its long ride to Mars and then robotically unfurled on the Martian surface. (NASA)

The Mastcam-Z imager aboard NASA’s Perseverance Mars rover, which is parked at “Van Zyl Overlook” and serving as a communications base station, captured video of Ingenuity.

The Ingenuity team has been pushing the helicopter’s limits by adding instructions to capture more photos of its own – including from the color camera, which captured its first images on the second flight. As with everything else about these flights, the additional steps are meant to provide insights that could be used by future aerial missions.

The helicopter’s black-and-white navigation camera, meanwhile, tracks surface features below, and this flight put the onboard processing of these images to the test. Ingenuity’s flight computer, which autonomously flies the craft based on instructions sent up hours before data is received back on Earth, utilizes the same resources as the cameras.

If Ingenuity flies too fast, the flight algorithm can’t track surface features.

On Earth, NASA sought to simulate those conditions in NASA’s Jet Propulsion Lab vacuum chambers, which were filled with wispy air consisting primarily of carbon dioxide. … Read more

The Hows and Whys of Mars Sample Return

Combining two images, this mosaic shows a close-up view of the rock target named “Yeehgo” taken by the SuperCam instrument on NASA’s Perseverance rover on Mars. To be compatible with the rover’s software, “Yeehgo” is an alternative spelling of “Yéigo,” the Navajo word for diligent.
(NASA/JPL-Caltech/LANL/CNES/CNRS/ASU/MSSS)

One of the fondest dreams and top priorities of space science for years has been  to bring a piece of Mars back to Earth to study in the kind of depth possible only in a cutting-edge laboratory.

While the instruments on Mars rovers can tell us a lot,  returning a sample to study here on Earth is seen as the  way to ultimately tease out the deepest secrets of the composition of Mars, its geological and geochemical history and possibly the presence of life, life fossils or of the precursor molecules  of life.

But bringing such a sample to Earth is extraordinarily difficult.  Unlike solar system bodies that have been sampled back on Earth — the moon, a comet and some asteroids — Mars has the remains of an atmosphere.  That means any samples would have to lift off in a rocket brought to Mars and with some significant propulsive power, a task that so far has been a technical bridge too far.

That is changing now and the Mars Sample Return mission has begun.  The landing of the Perseverance rover in Jezero Crater on Mars signaled that commencement and the rover will be used to identify, drill into and collect intriguing bits of Mars.  This is a long-term project, with the best case scenario seeing those Mars samples arriving on Earth in a decade.  So this entirely unprecedented, high-stakes campaign will be playing out for a long time.

“I think that Mars scientists would like to return as much sample as possible,” said Lindsay Hays, NASA Mars Sample Return deputy program scientist.  “Being able to return samples that we collected with purpose is how we take the next step in our exploration of Mars.”

“And it seems that there are still so many unknowns, even in our solar system, even with the planets right next door, that every time we do something new, we answer a couple of questions that we hoped to and but also find a whole bunch of new things that we never expected.”

“I am so excited to see what comes of this adventure.  And I think that is a feeling shared by Mars scientists and planetary scientists broadly.”… Read more

What Happened to All That Water on Ancient Mars? A New Theory With a Surprising Answer

How did Mars lose the surface water that was plentiful on its surface 3 to 4 billion years ago?  New research says it did not leave the planet but rather was incorporated on a molecular level into Martian minerals.  (NASA)

Once it became clear in the past decade that the surface of ancient Mars, the inevitable question arose regarding what happened to it all since the planet is today so very dry.  And the widely-accepted answer has been that the water escaped into space, especially after the once thicker atmosphere of Mars was stripped away.

But NASA-funded research just made public has a new and bold and very different answer:  Much of the water that formed rivers, lakes and deep oceans on Mars, the research concludes, sank below the planet’s surface and is trapped inside minerals in the planet’s rocky crust.

Since early Mars is now thought to have had as much surface water as half of the the Earth’s Atlantic Ocean — enough to cover most of Mars in at least 100 meters of water — that means huge volumes of water became incorporated into the molecular structure of clays, sulfates, carbonates, opals and other hydrated minerals.

While some of the early water surely disappeared from Mars via atmospheric escape, the new findings, published in the latest issue of Science, conclude that atmospheric loss can not account for much or most of its water loss — especially now that estimates of how much water once existed on the surface of the planet have increased substantially.

“Atmospheric escape doesn’t fully explain the data that we have for how much water actually once existed on Mars,” said Eva Scheller, lead author and a doctoral candidate at the California Institute of Technology.  The rate of water loss was found to be too slow to explain what happened.

Scheller and others at Caltech set out to find other explanations. Based on modeling and data collected by Mars orbiters, rovers and from meteorites, they concluded that between 30 and 99 percent of that very early Martian surface water can now be found trapped in the minerals of the planet’s crust.

Mars mudstone, as imaged by the Curiosity rover.  (NASA/JPL-Caltech)

As described in a release for NASA’s Jet Propulsion Laboratory, the team studied the quantity of water on Mars over time in all its forms (vapor, liquid, and ice) and the chemical composition of the planet’s current atmosphere and crust through the analysis of meteorites as well as using data provided by Mars rovers and orbiters. … Read more

NASA’s Perseverance Rover Lands on Mars — The Third Martian Arrival in a Week

This true-color Mars globe includes Terra Meridiani, the region where NASA’s Opportunity rover explored from 2004 to 2018.  Two more Mars rovers — one from NASA and the other from China — are scheduled to land this week and then later in the year. (NASA/Greg Shirah)

Mars is receiving visitors these days.  Quite a few of them.

The most prominent visitor is NASA’s Perseverance rover,  which made a difficult but smooth precision landing at 3.55 ET  this afternoon.

The rover now sits in Jezero Crater, in an area that clearly once had lots of water flowing.   The site was selected, in part, because the Perseverance rover’s official mission includes — for the first time since the mid 1970s — an effort to find signs of long ago life.

Perseverance will join the Curiosity rover on Mars, that pioneering machine that has revolutionized our understanding of the planet since it landed in 2012  The Curiosity and Perseverance rovers are similar in design but carry different instruments with different goals.

A key difference:  Curiosity was tasked with determining whether Mars had once been habitable and found that it definitely had been, with flowing rivers, large lakes and necessary-for-life organic compounds.  Perseverance will take another scientific step forward and search for signs that Mars actually was once inhabited.

Perseverance also joins China’s Tianwen-1 (“heavenly questions”) probe,  which went into orbit around Mars last week.  It is the first Chinese spacecraft to arrive at Mars, and later this spring or summer the Chinese space agency will attempt to land a rover as well on the planet’s northern plains..

And then there’s the Hope spacecraft which entered into Mars orbit last week as well.  Launched by the United Arab Emirates, it was placed in a wide orbit so it could study the planet’s weather and climate systems, which means it also can see the full planet in one view.

These spacecraft will join several others on or orbiting Mars, making this by far the busiest time ever for exploration of Mars — a real milestone.

NASA’s Perseverance rover will land in Jezero Crater. This image was produced using instruments on NASA’s Mars Reconnaissance Orbiter, which helps identify potential landing sites for future missions. On ancient Mars, water carved channels and transported sediments to form fans and deltas within lake basins, as is clearly visible at here at Jezaro Crater (NASA/JPL-Caltech/ASU)

That the Perseverance mission has a formal goal of searching for ancient signs of life is a big deal, and involves a lot of history.… Read more

Japan’s Hayabusa2 Mission Returns to Earth

Fireball created by the Hayabusa2 re-entry capsule as it passes through the Earth’s atmosphere towards the ground (JAXA).

In the mission control room in Japan, all eyes were fixed on one of the large screens that ran along the far wall. The display showed the night sky, with stars twinkling in the blackness. We were waiting for a delivery from space.

Japan’s Hayabusa2 mission launched from the Tanegashima Space Center on December 3, 2014. The spacecraft was headed to asteroid Ryugu, with the intention of studying the tiny world and collecting a sample to return to Earth.

The mission would prove to be an incredible success. Not only did the spacecraft gather two samples from the asteroid, but it was the first mission to deploy autonomous rovers to explore an asteroid’s surface, generate an artificial crater in order to study the asteroid’s structure and collect a sample of the interior, and additionally, deploy a lander to make scientific measurements from the surface itself. The mission finale was to return the samples safely back to Earth on December 6, 2020. The grains in that sample container may hold clues as to how the Earth became habitable.

Ryugu is an example of a C-type or “carbonaceous” asteroid. These asteroids have undergone relatively little change since the start of the solar system, and are thought to contain hydrated minerals (minerals containing water in their structure) and possible organics. It is this class of asteroid that may have crashed into the early Earth and delivered the necessary tools for life to begin. Analysis of the Ryugu sample could therefore tell us about our own beginnings and how terrestrial planets develop habitable conditions.

Images before and after the first touchdown of Hayabusa2 on asteroid Ryugu, taken with CAM-H on February 21, 2019 (animation plays at 5x speed) (JAXA).

As the Hayabusa2 spacecraft drew near the Earth, five “trajectory control manoeuvres” (TCMs) were planned. The first four of these were designed to put the spacecraft onto a collision course with the Earth, aimed at the Woomera desert in Australia. The re-entry capsule would then be released, and the spacecraft would make a final manoeuvre to divert onto an orbit that swept past the Earth and back into deep space.

Despite the smooth progress so far, there were concerns. The capsule release mechanism had not been tested since launch six years previously and it was always possible that separation would fail.… Read more

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