Goddard Space Flight Center

Tag: Goddard Space Flight Center

NASA Needs Your Help in the Search for Alien Life

October 11, 2020
ExoNews Editor

Article by Becky Ferreira October 2, 2020 (vice.com)

• Since the 1990s, scientists have discovered thousands of exoplanets throughout our galaxy contain a dizzying variety of extraterrestrial environments, some of which may host life.

• On September 29th, NASA launched the citizen science project ‘Planet Patrol’ on Zooniverse, inviting volunteers to join the hunt for new exoplanets by examining images snapped by the Transiting Exoplanet Survey Satellite (TESS), which has been in orbit around Earth since 2018.
• Veselin Kostov, a research scientist at NASA’s Goddard Space Flight Center in Maryland and the SETI Institute in California, said the project has already attracted more than 1,600 participants who have collectively delivered 100,000 individual classifications in just three days.

• “Citizen science projects are a great way to engage our built-in, never-ending curiosity about the world we live in,” says Kostov. Planet Patrol can also “promote a sense of a community pursuing the common goal of understanding the universe and our place in it.”

• The TESS satellite is designed to spot exoplanets as they pass in front of the stars they orbit, causing the star’s brightness to fade slightly. If these light dips occur at regular intervals, it’s a good sign that a planet may be present. Once the existence of an exoplanet has been confirmed, scientists can conduct follow-up observations that reveal basic properties of the distant world, including whether it might be habitable. For this reason, exoplanet-hunting is an important component of the search for extraterrestrial intelligence (SETI).

• Scientists use automated software and machine learning to sift through the hundreds of thousands of pictures TESS takes each year. These systems can flag likely exoplanets to a certain extent, but they have trouble recognizing “imposter” false transit events. For instance, binary systems that contain two stars can produce a light dip, or instrument and/or astrophysical noise that distort the TESS images, which automated processing software might accidentally catalog as an exoplanet candidate. “The human eye is very good at quickly and reliably spotting such image distortions,” says Kostov.

• Planet Patrol participants are tasked with evaluating the quality of TESS images used to distinguish between potential false positives and bona-fide planet candidates. It’s the latest of several exoplanet-hunting platforms that have benefitted from the time and dedication of amateur space enthusiasts, such as Planet Hunters and Exoplanet Explorers. Says Kostov, “My hope is that the project sparks a continuous interest in exoplanets in particular and in astrophysics in general.”

Since the 1990s, scientists have discovered thousands of exoplanets, which are worlds that orbit stars other than the Sun, revealing that our galaxy

contains a dizzying variety of extraterrestrial environments, some of which may host life.

Now, NASA is inviting volunteers to join the hunt for new exoplanets by examining images snapped by the Transiting Exoplanet Survey Satellite (TESS), which has been in orbit around Earth since 2018.

On Monday, NASA launched the citizen science project Planet Patrol on Zooniverse, enabling anyone with an internet connection to spot and classify likely exoplanets in TESS’ starry images.

Veselin Kostov, a research scientist at NASA’s Goddard Space Flight Center in Maryland and the SETI Institute in California, said the project already has more than 1,600 participants who have collectively delivered 100,000 individual classifications in just three days.

“Citizen science projects are a great way to engage our built-in, never-ending curiosity about the world we live in—be it our own planet or a planet a hundred light years away,” said Kostov in an email.

Planet Patrol can also “promote a sense of a community pursuing the common goal of understanding the universe and our place in it,” Kostov added, which is especially welcome at a time when many people are stuck at home due to the Covid-19 pandemic.

TESS is designed to spot exoplanets as they pass in front of the stars they orbit, which is known as a transit. Transits cause the star’s brightness to fade slightly, and if these light dips occur at regular intervals, it’s a good sign that a planet may be present.

1:02 minute NASA “Planet Patrol” video (‘NASA Goddard’ YouTube)

READ ENTIRE ARTICLE

FAIR USE NOTICE: This page contains copyrighted material the use of which has not been specifically authorized by the copyright owner. ExoNews.org distributes this material for the purpose of news reporting, educational research, comment and criticism, constituting Fair Use under 17 U.S.C § 107. Please contact the Editor at ExoNews with any copyright issue.

Scientists Use Moon as Mirror to Detect Extraterrestrial Life

August 21, 2020
ExoNews Editor

Article by Claire Bugos August 10, 2020 (smithsonianmag.com)

• In January 2019, there was a total lunar eclipse. During a two-day period, light from the Sun passed through the Earth’s atmosphere and hit the Moon, and was reflected back toward the Earth. The Hubble Space Telescope was able to intercept and gather data from this ultraviolet light. Though similar ground-based studies have been done before, this is the first time that scientists have used a space telescope to capture ultraviolet wavelengths. From this data, scientists from NASA and the European Space Agency are able to analyze the Earth’s own atmospheric spectrum. They reported their findings in an article published August 6 in The Astronomical Journal. (see 3-minute NASA video below)

• The main focus was on the Earth’s protective ozone layer. Ozone absorbs ultraviolet radiation. During the eclipse, Hubble detected lower amounts of UV radiation from the light reflected off the Moon than is present from unfiltered sunlight. Therefore, the Earth’s atmosphere absorbed some of it. If they can simulate this with a distant exoplanet, they can determine whether that planet’s atmosphere contains ozone. And along with oxygen, the detection of an ozone layer is considered an indication of possible life on that planet.

• Using this unique method, scientists can simulate observations of exoplanets. When an exoplanet crosses in front of its star, the star light is filtered through the planet’s atmosphere, creating a “halo” effect. Chemicals in the atmosphere filter out certain colors of starlight. Therefore, scientists can determine that planet’s atmospheric composition.

• “But how would we know a habitable or an uninhabited planet if we saw one?” queries Allison Youngblood of the Laboratory for Atmospheric and Space Physics, and lead researcher of Hubble’s observations. By developing a model of the Earth’s chemical spectrum, scientists can use this as a template for categorizing the atmospheres of exoplanets in other solar systems.

• The age of the planet is also be taken into account when determining its ability to host life. Earth had low concentrations of oxygen for more than a billion years, while organisms used photosynthesis to build the ozone layer. So it may be challenging to detect ozone in younger planets. Still, ultraviolet may be “the best wavelength to detect photosynthetic life on low-oxygen exoplanets,” says Giada Arney of NASA’s Goddard Space Flight Center and a co-author of the study.

• The Hubble telescope was launched in 1990, even before astronomers first discovered exoplanets. While its ability to observe extraterrestrial atmospheres is “remarkable,” NASA says future observations of Earth-sized planets will require much larger telescopes and longer observational periods, which the James Webb Space telescope, scheduled to launch in 2021, will provide.

In the quest to discover life beyond Earth, scientists are harnessing a very large and proximate tool—the moon.

During a total lunar eclipse in January 2019, the moon acted like a giant mirror, reflecting sunlight that had passed

through our atmosphere back toward Earth, reports Chelsea Gohd for Space.com. The Hubble Space Telescope, which was positioned between the Earth and moon, intercepted the reflected ultraviolet light for scientists to analyze.

Scientists from NASA and the European Space Agency studied the reflected light from a lunar eclipse during a two-day window. They reported their findings in an article published August 6 in The Astronomical Journal.

For the first time, scientists used a space telescope to capture ultraviolet wavelengths. Though similar ground-based studies have been done before, using a space telescope for this observation allows scientists to simulate future observations of exoplanets, Space.com reports.

The goal was for the telescope to detect the Earth’s ozone layer. The ozone molecule that makes up the Earth’s protective layer absorbs ultraviolet radiation. During the eclipse, Hubble detected lower amounts of UV radiation from the light reflected off the moon than is present from unfiltered sunlight, meaning the Earth’s atmosphere must have absorbed some of it, according to a NASA press release.

If scientists are able to detect an ozone layer or oxygen on a neighboring exoplanet, there’s a possibility that the planet may harbor life. On Earth, oxygen is often produced by life forms, especially those that photosynthesize. If scientists detect an oxygen-rich atmosphere on an exoplanet, especially if the amount of oxygen varies seasonally, there is a chance that it also hosts life. But scientists would need to further analyze the atmosphere using other tools before determining if it’s life-hosting, Allison Youngblood of the Laboratory for Atmospheric and Space Physics, and lead researcher of Hubble’s observations, says in the press release.

3-minute video “Hubble Views Moon to Study Earth” (‘NASA Goddard’ YouTube)

READ ENTIRE ARTICLE