Exoplanet WASP-96 b Atmospheric Characteristics

A transmission spectrum made from a single observation using Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) reveals atmospheric characteristics of the hot gas giant exoplanet WASP-96 b.

A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves across the star, to the unfiltered starlight detected when the planet is beside the star. Each of the 141 data points (white circles) on this graph represents the amount of a specific wavelength of light that is blocked by the planet and absorbed by its atmosphere.

In this observation, the wavelengths detected by NIRISS range from 0.6 microns (red) to 2.8 microns (in the near-infrared). The amount of starlight blocked ranges from about 13,600 parts per million (1.36 percent) to 14,700 parts per million (1.47 percent).

Researchers are able to detect and measure the abundances of key gases in a planet’s atmosphere based on the absorption pattern – the locations and heights of peaks on the graph: each gas has a characteristic set of wavelengths that it absorbs. The temperature of the atmosphere can be calculated based in part on the height of the peaks: a hotter planet has taller peaks. Other characteristics, like the presence of haze and clouds, can be inferred based on the overall shape of different portions of the spectrum.

The gray lines extending above and below each data point are error bars that show the uncertainty of each measurement, or the reasonable range of actual possible values. For a single observation, the error on these measurements is remarkably small.

The blue line is a best-fit model that takes into account the data, the known properties of WASP-96 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere. Researchers can vary the parameters in the model – changing unknown characteristics like cloud height in the atmosphere and abundances of various gases – to get a better fit and further understand what the atmosphere is really like. The difference between the best-fit model shown here and the data simply reflects the additional work to be done in analyzing and interpreting the data and the planet.

Although full analysis of the spectrum will take additional time, it is possible to draw a number of preliminary conclusions. The labeled peaks in the spectrum indicate the presence of water vapor. The height of the water peaks, which is less than expected based on previous observations, is evidence for the presence of clouds that suppress the water vapor features. The gradual downward slope of the left side of the spectrum (shorter wavelengths) is indicative of possible haze. The height of the peaks along with other characteristics of the spectrum is used to calculate an atmospheric temperature of about 1350°F (725°C).

This is the most detailed infrared exoplanet transmission spectrum ever collected, the first transmission spectrum that includes wavelengths longer than 1.6 microns with such high resolution and accuracy, and the first to cover the entire wavelength range from 0.6 microns (visible red light) to 2.8 microns (near-infrared) in a single shot. The speed with which researchers have been able to make confident interpretations of the spectrum is further testament to the quality of the data.

The observation was made using NIRISS’s Single-Object Slitless Spectroscopy (SOSS) mode, which involves capturing the spectrum of a single bright object, like the star WASP-96, in a field of view.

WASP-96 b is a hot gas giant exoplanet that orbits a Sun-like star roughly 1,150 light-years away, in the constellation Phoenix. The planet orbits extremely close to its star (less than 1/20th the distance between Earth and the Sun) and completes one orbit in less than 3½ Earth-days. The planet’s discovery, based on ground-based observations, was announced in 2014. The star, WASP-96, is somewhat older than the Sun, but is about the same size, mass, temperature, and color.

The background illustration of WASP-96 b and its star is based on current understanding of the planet from both NIRISS spectroscopy and previous ground- and space-based observations. Webb has not captured a direct image of the planet or its atmosphere.

NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.

Source: https://exoplanets.nasa.gov/resources/2326/exoplanet-wasp-96-b-atmospheric-characteristics/

The MAVEN orbiter’s main antenna is pointed toward Earth as it recovers, limiting science operations.

A navigation system glitch that struck NASA’s MAVEN orbiter at Mars earlier this year has hobbled the spacecraft’s ability to conduct science and study the Red Planet’s atmosphere.

The MAVEN spacecraft, which has orbited Mars since 2014, went into a protective “safe mode” on Feb. 22 when its vital inertial measurement units “began exhibiting anomalous behavior,” NASA officials wrote in a May 18 update. While in safe mode, a spacecraft shuts down all science and awaits instructions from its flight controllers on how to recover.

In the weeks that followed, NASA managed to revive MAVEN from safe mode, but in a limited capacity. The orbiter is in a stable orbit with its primary antenna pointed at Earth to maintain high-rate communications with its flight control team. 

“In this configuration, however, MAVEN cannot perform communications relays for other spacecraft on Mars and is performing only limited science observations,” NASA officials wrote in the update (opens in new tab). “The mission team began science instrument recovery on April 20.” The orbiter normally serves as a communication relay for NASA’s Curiosity rover and Perseverance rover on Mars to beam the latest images and research from the Martian surface to Earth.

MAVEN’s inertial measurement unit (IMU) system relies on ring laser gryroscopes, that detect the spaceraft’s inertial motion, and four reaction wheels arranged in a four-sided pyramid that can spin independently to position the orbiter in the proper orientation, according to a NASA press kit (opens in new tab). The orbiter is also equipped with two star tracker cameras that can take images of stars and feed them into a stellar detection algorithm to help the spacecraft determine its orientation in space.

NASA officials reported that MAVEN was in safe mode until April 19, when flight controllers switch the spacecraft from its IMUs to the star-tracking system in what is known as “all-stellar mode.”

“All MAVEN’s science instruments are currently online, but not all of them have been able to take data while the high gain antenna is restricted to pointing toward Earth,” NASA officials wrote in the update. “The team is currently working to finish checkouts of ‘all stellar’ mode to enable the spacecraft to operate in other orientations prior to resuming nominal science and relay operations by the end of the month.”

NASA launched the MAVEN mission (its name is short for Mars Atmosphere and Volatile EvolutioN mission) in November 2013 and arrived at the Red Planet in October 2014. Its mission is to study how Mars lost its surface water to become the dusty red world we see today. Last month, NASA extended the MAVEN mission, which originally cost $671 million, by another three years to allow the orbiter to continue its science work.

Source: https://www.space.com/mars-maven-orbiter-glitch-stalls-science

Meet ignimbrite, a volcanic rock found here on Earth and potentially on Mars.

An unusual rock type spotted by two Mars rovers may indicate that the Martian landscape was shaped by extremely violent volcanic eruptions.

The Nili Fossae region of Mars, which includes the Jezero Crater that NASA’s Perseverance rover is currently exploring, is filled with bedrock laden with the volcanic mineral olivine. That same olivine-rich bedrock was also found at the Gusev Crater, where NASA’s Spirit Rover roamed until its demise in 2010. But the connection between the regions wasn’t made until now, by a team led by planetary geologist Steve Ruff of Arizona State University. The researchers examined data from multiple Mars rovers to confirm the geologic similarities, which indicates the local rocks might have formed by similar processes. Then the scientists compared Spirit’s images of the Gusev Crater rock with images of Earth rocks.

“That was a eureka moment,” Ruff said in a statement. “I was seeing the same kind of textures in the rocks of Gusev crater as those in a very specific kind of volcanic rock found here on Earth.”

That rock is ignimbrite, which is created from the ash, pumice and pyroclastic flows of powerful volcanic eruptions. “No one had previously suggested ignimbrites as an explanation for olivine-rich bedrock on Mars,” Ruff said. “And it’s possible that this is the kind of rock that the Perseverance rover has been driving around on and sampling for the past year.”

Although researchers have long theorized that volcanism was responsible for producing the Nili Fossae — olivine is, after all, a volcanic mineral — the identification of ignimbrite, if proven accurate, would indicate that the eruptions were more cataclysmic than previously thought.

“Imagine a ground-hugging cloud of hot gasses and nearly molten ash and pumice flowing through the landscape for dozens of miles and piling up in layers up to hundreds of feet thick in just a few days,” Ruff said about eruptions that have produced this type of rock on Earth.

To confirm the presence of ignimbrite on Mars, the scientists say they will have to study the rocks in a terrestrial lab another argument for the planned Mars Sample Return mission to ferry Perseverance’s samples back to Earth.

The results of this study will be published in a paper in the journal Icarus in July.

Source: https://www.space.com/mars-rock-violent-volcanic-eruption-ignimbrite

Russia halts Soyuz rocket launches from South America over European sanctions on Ukraine invasion

The announcement stalls Soyuz launches from French Guiana with European launch provider Arianespace

“In response to EU sanctions against our enterprises, Roscosmos is suspending cooperation with European partners in organizing space launches from the Kourou cosmodrome and withdrawing its personnel, including the consolidated launch crew, from French Guiana,” Roscosmos chief Dmitry Rogozin said in a Twitter statement on Saturday (Feb. 26) according to a translation from Russian.

The Russian space agency Roscosmos is stopping all Soyuz rocket launches from Europe’s spaceport in French Guiana due to European Union sanctions on Russia’s invasion of Ukraine. 

Russia is also recalling 87 Russian workers from Europe’s South American spaceport in French Guiana who support Soyuz rocket launches for Roscosmos and the Russian companies NPO Lavochkin a, Progress RCC and TsENKI, according to a second Twitter statement from Roscosmos.

“The issue of the departure of Russian employees is being worked out,” Roscosmos wrote. Russia’s moves come as European Union nations, the United States and other countries have levied severe economic sanctions on Russia following the country’s invasion of Ukraine on Thursday (Feb. 24). 

Russia’s Soyuz rockets are used by the European launch provider Arianespace to launch satellites from the Guiana Space Center near Kourou, French Guiana, as well as from the Baikonur Cosmodrome in Kazakhstan (where Russia regularly launches its own Soyuz missions). The most recent Soyuz rocket to launch from Guiana Space Center lifted off on Feb. 10 carrying 34 OneWeb internet satellites.

Arianespace, based in France, also uses its own European Ariane 5 heavy-lift rocket and Vega rocket for smaller launches from French Guiana. 

Arianespace’s next Soyuz launch was scheduled for early April to launch two Galileo navigation satellites into orbit for the European Union’s Galileo constellation. That mission will almost certainly be delayed due to Russia’s announcement on Saturday. 

Thierry Breton, the European Commissioner for Space, said Russia’s decision to halt Soyuz launches with Europe will not interrupt any services for users of the Galileo satellites or of the E.U.’s Copernicus Earth observation satellite program. 

“I confirm that this decision has no consequences on the continuity and quality of the Galileo and Copernicus services,” Breton said in the statement. “Nor does this decision put the continued development of these infrastructures at risk.”

Breton added that the E.U. and its member states are “ready to act decisively” in order to “protect these critical infrastructures in case of aggression,” and that it will  “continue to develop Ariane 6 and Vega C to ensure Europe’s strategic autonomy in the area of launchers.”

The Ariane 6 rocket is Europe’s successor to the Ariane 5 and is expected to make its first flight sometime later in 2022. The Vega C rocket is a follow-on to Europe’s Vega rocket that is designed to reach more orbits and carry more diverse payloads for the same cost. The European Space Agency and Arianespace are working to develop the Ariane 6 and Vega-C rockets. 

On Friday (Feb. 25), ESA Director-General Josef Aschbacher said in a statement that the European space officials were “closely monitoring what’s happening” in Ukraine while weighing any response. ESA is working closely with Russia’s space program to launch the European ExoMars rover mission to Mars later this year.

In addition to calling off Soyuz launches from French Guiana, Rogozin also announced Saturday that he no longer felt a joint Russian-U.S. collaboration on Russia’s planned Venera-D mission to Venus was necessary, given the ongoing sanctions. 

In a separate statement, Rogozin wrote that he found it “inappropriate” for any continued participation of the U.S. in the Russian Venus mission, which was slated to launch sometime in the 2020s. NASA scientists began talks with Russia to participate in the Venera-D mission in 2017. 

Source: https://www.space.com/russia-halts-soyuz-launches-french-guiana

On January 16, 1969, two crewed spacecraft docked in orbit for the first time. 

When the Soviet Union launched the Soyuz 4 spacecraft, only one cosmonaut was on board. But it returned with a crew of three after two cosmonauts from Soyuz 5 transferred spacecrafts in orbit.

Soyuz 4 safely returned to Earth, but the one unlucky cosmonaut who was left behind in Soyuz 5 had a pretty rough landing.   

During reentry, the service module failed to separate from the descent module, and the spacecraft got turned upside-down. To top it off, the parachutes and soft-landing rockets failed to deploy properly. That cosmonaut, Boris Volynov, miraculously survived the crash — but he did lose a few teeth.

Source: https://www.space.com/39251-on-this-day-in-space.html