Tuesday, June 26, 2018

Will We Know Life When We See It? | NASA

Image: an artist's conception of what life could look like on the surface of a distant planet.

June 25, 2018: In the last decade, we have discovered thousands of planets outside our solar system and have learned that rocky, temperate worlds are numerous in our galaxy. The next step will involve asking even bigger questions. Could some of these planets host life? And if so, will we be able to recognize life elsewhere if we see it?

A group of leading researchers in astronomy, biology and geology has come together under NASA's Nexus for Exoplanet System Science, or NExSS, to take stock of our knowledge in the search for life on distant planets and to lay the groundwork for moving the related sciences forward.

"We're moving from theorizing about life elsewhere in our galaxy to a robust science that will eventually give us the answer we seek to that profound question: Are we alone?" said Martin Still, an exoplanet scientist at NASA Headquarters, Washington.

In a set of five review papers published last week in the scientific journal Astrobiology, NExSS scientists took an inventory of the most promising signs of life, called biosignatures. The paper authors include four scientists from NASA's Jet Propulsion Laboratory in Pasadena, California. They considered how to interpret the presence of biosignatures, should we detect them on distant worlds. A primary concern is ensuring the science is strong enough to distinguish a living world from a barren planet masquerading as one.

The assessment comes as a new generation of space and ground-based telescopes are in development. NASA's James Webb Space Telescope will characterize the atmospheres of some of the first small, rocky planets. There are plans for other observatories—such as the Giant Magellan Telescope and the Extremely Large Telescope, both in Chile—to carry sophisticated instruments capable of detecting the first biosignatures on faraway worlds.

Through their work with NExSS, scientists aim to identify the instruments needed to detect potential life for future NASA flagship missions. The detection of atmospheric signatures of a few potentially habitable planets may possibly come before 2030, although determining whether the planets are truly habitable or have life will require more in-depth study.

Since we won't be able to visit distant planets and collect samples anytime soon, the light that a telescope observes will be all we have in the search for life outside our solar system. Telescopes can examine the light reflecting off a distant world to show us the kinds of gases in the atmosphere and their "seasonal" variations, as well as colors like green that could indicate life.

These kinds of biosignatures can all be seen on our fertile Earth from space, but the new worlds we examine will differ significantly. For example, many of the promising planets we have found are around cooler stars, which emit light in the infrared spectrum, unlike our sun's high emissions of visible-light.

"What does a living planet look like?" said Mary Parenteau, an astrobiologist and microbiologist at NASA's Ames Research Center in Silicon Valley and a co-author. "We have to be open to the possibility that life may arise in many contexts in a galaxy with so many diverse worlds—perhaps with purple-colored life instead of the familiar green-dominated life forms on Earth, for example. That's why we are considering a broad range of biosignatures."

The scientists assert that oxygen—the gas produced by photosynthetic organisms on Earth—remains the most promising biosignature of life elsewhere, but it is not foolproof. Abiotic processes on a planet could also generate oxygen. Conversely, a planet lacking detectable levels of oxygen could still be alive - which was exactly the case of Earth before the global accumulation of oxygen in the atmosphere.

"On early Earth, we wouldn't be able to see oxygen, despite abundant life," said Victoria Meadows, an astronomer at the University of Washington in Seattle and lead author of one of the papers. "Oxygen teaches us that seeing, or not seeing, a single biosignature is insufficient evidence for or against life—overall context matters."

Rather than measuring a single characteristic, the NExSS scientists argue that we should be looking at a suite of traits. A planet must show itself capable of supporting life through its features, and those of its parent star.

The NExSS scientists will create a framework that can quantify how likely it is that a planet has life, based on all the available evidence. With the observation of many planets, scientists may begin to more broadly classify the "living worlds" that show common characteristics of life, versus the "non-living worlds."

"We won't have a 'yes' or 'no' answer to finding life elsewhere," said Shawn Domagal-Goldman, an astrobiologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and a co-author. "What we will have is a high level of confidence that a planet appears alive for reasons that can only be explained by the presence of life."

Learn more about NExSS:
https://nexss.info/

Credit: NASA/Jet Propulsion Laboratory
Release Date: June 25, 2018


#NASA #Astronomy #Space #Science #Exoplanets #Planets #NExSS #Stars #Life #Atmosphere #Biosignatures #Astrobiology #Earth #SolarSystem #Art #Illustration #JPL #STEM #Education

Asteroid Trails and Abell 370 | Hubble

As if this Hubble Space Telescope picture isn't cluttered enough with myriad galaxies, nearby asteroids photobomb the image, their trails sometimes mimicking background astronomical phenomena.

The stunningly beautiful galaxy cluster Abell 370 contains an astounding assortment of several hundred galaxies tied together by the mutual pull of gravity. Located approximately 4 billion light-years away in the constellation Cetus, the Sea Monster, this immense cluster is a rich mix of a variety of galaxy shapes.

Entangled among the galaxies are thin, white trails that look like curved or S-shaped streaks. These are trails from asteroids that reside, on average, only about 260 million kilometers from Earthright around the corner in astronomical terms. The trails appear in multiple Hubble exposures that have been combined into one image. Of the 22 total asteroid sightings for this field, five are unique objects. These asteroids are so faint that they were not previously identified.

The asteroid trails look curved due to an observational effect called parallax. As Hubble orbits around Earth, an asteroid will appear to move along an arc with respect to the vastly more distant background stars and galaxies. The motion of Earth around the Sun, and the motion of the asteroids along their orbits, are other contributing factors to the apparent skewing of asteroid paths.

All the asteroids were found manually, the majority by "blinking" consecutive exposures to capture apparent asteroid motion. Astronomers found a unique asteroid for every 10 to 20 hours of exposure time.

These asteroid trails should not be confused with the mysterious-looking arcs of blue light that are actually distorted images of distant galaxies behind the cluster. Many of these far-flung galaxies are too faint for Hubble to see directly. Instead, in a dramatic example of "gravitational lensing," the cluster functions as a natural telescope, warping space and affecting light traveling through the cluster toward Earth.

The Frontier Fields program is a collaboration among several space telescopes and ground-based observatories to study six massive galaxy clusters and their effects. Using a different camera, pointing in a slightly different direction, Hubble photographed six so-called "parallel fields" at the same time it photographed the massive galaxy clusters. This maximised Hubble's observational efficiency in doing deep space exposures. These parallel fields are similar in depth to the famous Hubble Deep Field, and include galaxies about four-billion times fainter than can be seen by the human eye.

This image was assembled from several exposures taken in visible and infrared light. The field's position on the sky is near the ecliptic, the plane of our Solar System. This is the zone in which most asteroids reside, which is why Hubble astronomers saw so many crossings. Hubble deep-sky observations taken along a line-of-sight near the plane of our Solar System commonly record asteroid trails.

Credit:
NASA, ESA, and B. Sunnquist and J. Mack (STScI)
Acknowledgment: NASA, ESA, and J. Lotz (STScI) and the HFF Team
Release Date: November 6, 2017


#NASA #Hubble #Astronomy #Space #Science #Galaxies #Abell370 #Galaxy #Cluster #Cetus #Asteroids #Asteroid #SolarSystem #Cosmos #Universe #Telescope #ESA #Goddard #GSFC #STScI #STEM #Education

Monday, June 25, 2018

Northern Germany | International Space Station



ESA Astronaut Alexander Gerst: "This surprising view during our second earth orbit made me think of home—with a smile on my face. I am looking forward to half a year in space and returning home afterwards!"

Follow Alexander and the Horizons mission:
http://bit.ly/AlexanderGerstESA and on bit.ly/HorizonsBlogESA

Credit: Alexander Gerst/European Space Agency (ESA)
Release Date: June 24, 2018


#NASA #Space #ISS #Science #Earth #Europe #Germany #Deutschland #Poland #Polska #Sweden #Swede #Denmark #Danmark #Expedition56 #Human #Spaceflight #Spacecraft #Photography #STEM #Education #International #OrbitalPerspective #OverviewEffect

Globular Cluster NGC 6139 | Hubble

This rich and dense smattering of stars is a massive globular cluster, a gravitationally-bound collection of stars that orbits the Milky Way. Globular clusters are denser and more spherical than open star clusters like the famous Pleiades. They typically contain hundreds of thousands of stars that are thought to have formed at roughly the same time.

Studies have shown that this globular cluster, named NGC 6139, is home to an aging population of stars. Most globular clusters orbiting the Milky Way are estimated to be over 10 billion years old; as a result they contain some of the oldest stars in our galaxy, formed very early in the galaxy’s history. However, their role in galactic evolution is still a matter of study.

This cluster is seen roughly in the direction of the center of the Milky Way, in the constellation of Scorpius (The Scorpion). This constellation is a goldmine of fascinating astronomical objects. Hubble has set its sights on Scorpius many times to observe objects such as the butterfly-like Bug Nebula, surprising binary star systems, and other dazzling globular clusters.

Credit: ESA/Hubble & NASA
Release Date: June 25, 2019


#NASA #Astronomy #Space #Science #GlobularCluster #NGC6139 #Scorpius #Stars #Cosmos #Universe #Telescope #ESA #Goddard #GSFC #STScI #STEM #Education

Saturday, June 23, 2018

CubeSat Launch | International Space Station

U.S. Astronaut Ricky Arnold: "Resistance wasn’t futile. NanoRacks RemDeb satellite deployed on Wednesday morning from the International Space Station." 

Credit: NASA Astronaut Ricky Arnold
Image Date: June 17, 2018
Release Date: June 19, 2018


#NASA #Space #ISS #Science #Earth #CubeSat #RemDeb #NanoRacks #JAXA #Japan #日本 #Astronaut #RickyArnold #UnitedStates #Expedition56 #Human #Spaceflight #Spacecraft #Photography #STEM #Education #StarTrek #ScienceFiction #TheBorg #OrbitalPerspective #OverviewEffect

Deep Space Gateway Plans | This Week@NASA

Week of June 22, 2018 | The third meeting of the National Space Council, seeking a partnership to power our Gateway, and—an educational activity that’s quite a blast...a few of the stories to tell you about—This Week at NASA!

Credit: National Aeronautics and Space Administration (NASA)
Duration: 3 minutes, 4 seconds
Release Date: June 22, 2018


#NASA #Space #Astronomy #Science #Gateway #DeepSpace #Exploration #Moon #Mars #JourneyToMars #NEO #Asteroids #SolarSystem #Students #Rockets #Rocketry #Wallops #Virginia #UnitedStates #STEM #Education #HD #Video

Friday, June 22, 2018

Hubble illuminates cluster of diverse galaxies

This image from the NASA/ESA Hubble Space Telescope shows the diverse collection of galaxies in the cluster Abell S0740 that is over 450 million light-years away in the direction of the constellation Centaurus. The giant elliptical ESO 325-G004 looms large at the cluster's center. Hubble resolves thousands of globular star clusters orbiting ESO 325-G004. Globular clusters are compact groups of hundreds of thousands of stars that are gravitationally bound together. At the galaxy's distance they appear as pinpoints of light contained within the diffuse halo. This image was created by combining Hubble science observations taken in January 2005 with Hubble Heritage observations taken a year later to form a 3-color composite. The filters that isolate blue, red and infrared light were used with the Advanced Camera for Surveys aboard Hubble.

Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)
Release Date: June 21, 2018


#NASA #Hubble #ESO #Astronomy #Space #Science #Einstein #Relativity #GeneralRelativity #EinsteinRing #Lens #Galaxy #ESO325G004 #Cosmos #Universe #Telescope #VLT #ESA #GSFC #Goddard #STScI #STEM #Education

NASA's Space to Ground: Clearing the Cosmos

Week of June 22, 2018 | NASA's Space to Ground is your weekly update on what's happening aboard the International Space Station. 

Credit: NASA's Johnson Space Center
Duration: 2 minutes, 45 seconds
Release Date: June 22, 2018


#NASA #Space #ISS #Science #Earth #SpaceDebris #SpaceJunk #CubeSats #SpaceX #CRS15 #Commercial #Cargo #Astronauts #DrewFeustel #RickyArnold #ESA #DLR #AlexanderGerst #Europe #Germany #Deutschland #SerenaAuñónChancellor #UnitedStates #Expedition56 #Human #Spaceflight #Spacecraft #JSC #Houston #Texas #STEM #Education #HD #Video

Thursday, June 21, 2018

Hubble proves Einstein correct on galactic scales

Most precise general relativity test outside Milky Way
June 21, 2018: An international team of astronomers using the NASA/ESA Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope has made the most precise test of general relativity yet outside our Milky Way. The nearby galaxy ESO 325-G004 acts as a strong gravitational lens, distorting light from a distant galaxy behind it to create an Einstein ring around its centre. By comparing the mass of ESO 325-G004 with the curvature of space around it, the astronomers found that gravity on these astronomical length-scales behaves as predicted by general relativity. This rules out some alternative theories of gravity.

Image of Einstein ring:
An image of the nearby galaxy ESO 325-G004, created using data collected by the NASA/ESA Hubble Space Telescope and the MUSE instrument on the ESO’ Very Large Telescope. MUSE measured the velocity of stars in ESO 325-G004 to produce the velocity dispersion map that is overlaid on top of the Hubble Space Telescope image. Knowledge of the velocities of the stars allowed the astronomers to infer the mass of ESO 325-G004. The inset shows the Einstein ring resulting from the distortion of light from a more distant source by intervening lens ESO 325-004, which becomes visible after subtraction of the foreground lens light.

Using the NASA/ESA Hubble Space Telescope and European Southern Observatory’s Very Large Telescope (VLT), a team led by Thomas Collett (University of Portsmouth, UK), was able to perform the most precise test of general relativity outside the Milky Way to date.

The theory of general relativity predicts that objects deform spacetime, causing any light that passes by to be deflected and resulting in a phenomenon known as gravitational lensing. This effect is only noticeable for very massive objects. A few hundred strong gravitational lenses are known, but most are too distant to precisely measure their mass. However, the elliptical galaxy ESO 325-G004 is amongst the closest lenses at just 450 million light-years from Earth.

Using the MUSE instrument on the VLT the team calculated the mass of ESO 325-G004 by measuring the movement of stars within it. Using Hubble the scientists were able to observe an Einstein ring resulting from light from a distant galaxy being distorted by the intervening ESO 325-G004. Studying the ring allowed the astronomers to measure how light, and therefore spacetime, is being distorted by the huge mass of ESO 325-G004.

Collett comments: “We know the mass of the foreground galaxy from MUSE and we measured the amount of gravitational lensing we see from Hubble. We then compared these two ways to measure the strength of gravity—and the result was just what general relativity predicts, with an uncertainty of only nine percent. This is the most precise test of general relativity outside the Milky Way to date. And this using just one galaxy!”

General relativity has been tested with exquisite accuracy on Solar System scales, and the motions of stars around the black hole at the centre of the Milky Way are under detailed study, but previously there had been no precise tests on larger astronomical scales. Testing the long range properties of gravity is vital to validate our current cosmological model.

These findings may have important implications for models of gravity alternative to general relativity. These alternative theories predict that the effects of gravity on the curvature of spacetime are “scale dependent”. This means that gravity should behave differently across astronomical length-scales from the way it behaves on the smaller scales of the Solar System. Collett and his team found that this is unlikely to be true unless these differences only occur on length scales larger than 6000 light-years.

“The Universe is an amazing place providing such lenses which we can use as our laboratories,” adds team member Bob Nichol (University of Portsmouth). “It is so satisfying to use the best telescopes in the world to challenge Einstein, only to find out how right he was.”

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

This research was presented in a paper entitled “A precise extragalactic test of General Relativity” by Collett et al., to appear in the journal Science.

The international team is comprised of: Thomas E. Collett (Institute of Cosmology and Gravitation, University of Portsmouth, UK), Lindsay J. Oldham (Institute of Astronomy, University of Cambridge, UK, and Harvard College, Harvard-Smithsonian Center for Astrophysics, USA), Russell Smith (Centre for Extragalactic Astronomy, University of Durham, UK), Matthew W. Auger (Institute of Astronomy, University of Cambridge, UK), Kyle B. Westfall (ICG, Portsmouth, UK, and University of California, Santa Cruz, USA), David Bacon (ICG, Portsmouth, UK), Robert C. Nichol (ICG, Portsmouth, UK), Karen L. Masters (ICG, Portsmouth, UK), Kazuya Koyama (ICG, Portsmouth, UK) and Remco van den Bosch (Max Planck Institute for Astronomy, Garching, Germany).

Credit: ESO, ESA/Hubble, NASA
Release Date: June 21, 2018


#NASA #Hubble #ESO #Astronomy #Space #Science #Einstein #Relativity #GeneralRelativity #EinsteinRing #Lens #Galaxy #ESO325G004 #Cosmos #Universe #Telescope #VLT #ESA #GSFC #Goddard #STScI #STEM #Education #Infographic

Wednesday, June 20, 2018

Outpost | International Space Station




ESA Astronaut Alexander Gerst: "7 Billion people live on the planet beneath us. 6 single souls live in space. Unbelievable!"
-
"Außenposten. Auf dem Planeten unter uns leben 7 Milliarden Menschen. Im Weltraum leben 6 Menschen. Unglaublich!"

Follow Alexander and the Horizons mission:
http://bit.ly/AlexanderGerstESA and on bit.ly/HorizonsBlogESA

Credit: Alexander Gerst/European Space Agency (ESA)
Release Date: June 20, 2018


#NASA #Space #ISS #Science #Earth #Humanity #Astronaut #AlexanderGerst #Horizons #Europe #Germany #Deutschland #Expedition56 #Human #Spaceflight #Spacecraft #Photography #STEM #Education #International #OrbitalPerspective #OverviewEffect

Tuesday, June 19, 2018

Humanity's Cradle | NASA

NASA astronaut Drew Feustel is pictured tethered to the International Space Station just outside of the Quest airlock during a spacewalk he conducted with fellow NASA astronaut Ricky Arnold (out of frame) on June 14, 2018. During the six-hour, 49-minute spacewalk the duo installed high-definition cameras to provide enhanced views of commercial crew spacecraft, including the SpaceX Crew Dragon and the Boeing Starliner, as they approach and dock with the orbital laboratory.

Credit: NASA/JSC
Image Date: June 14, 2018


#NASA #Space #ISS #Science #Earth #Astronaut #Astronauts #Spacewalk #EVA #DrewFeustel #RickyArnold #SpaceX #CrewDragon #Boeing #Starliner #UnitedStates #Expedition56 #Human #Spaceflight #Spacecraft #JSC #Houston #Texas #STEM #Education

Earth View | Soyuz Spacecraft

ESA Astronaut Alexander Gerst: "The first photo I took out the window of our Soyuz after launch. I have no idea where it is. But I was surprised to see the Earth move much faster in the lower Soyuz orbit, compared to ISS."

Follow Alexander and the Horizons mission:
http://bit.ly/AlexanderGerstESA and on bit.ly/HorizonsBlogESA

Credit: Alexander Gerst/European Space Agency (ESA)
Release Date: June 18, 2018


#NASA #Space #ISS #Science #Earth #Soyuz #SoyuzMS09 #Союз #Astronaut #AlexanderGerst #Horizons #Europe #Germany #Deutschland #Expedition56 #Human #Spaceflight #Spacecraft #Photography #STEM #Education #International #OrbitalPerspective #OverviewEffect

Monday, June 18, 2018

Horizon | International Space Station

Alexander: "Horizon. Today, first day off after some of the busiest 10 days in my life. I thought long about which should be my first photo from space. When I saw this sunrise, I immediately knew this would be it. What a fascinating planet!"

Follow Alexander and the Horizons mission:
http://bit.ly/AlexanderGerstESA and on bit.ly/HorizonsBlogESA

"Horizont. Heute erster freier Tag nach zehn Tagen durcharbeiten. Habe lange überlegt, welches mein erstes Foto aus dem All sein sollte. Als ich diesen Sonnenaufgang gesehen habe, wusste ich die Antwort. Was für ein faszinierender Planet!"

Credit: European Space Agency (ESA)/NASA
Release Date: June 18, 2018


#NASA #Space #ISS #Science #Earth #Sunrise #Astronaut #AlexanderGerst #Horizons #Europe #Germany #Deutschland #Expedition56 #Human #Spaceflight #Spacecraft #Photography #STEM #Education #International #OrbitalPerspective #OverviewEffect

Crew Dragon Dreams | SpaceX Tribute Poster

Goal: Launching NASA Astronauts from U.S. Soil
Dragon 2.0. This is the next hurdle for SpaceX.
Learn more: www.spacex.com/crew-dragon
Commercial Crew: "The manned version of the Dragon spacecraft that has been successfully carrying cargo to the ISS for some time now. I believe there will be a high altitude abort test where a Falcon rocket will carry the Dragon to right before staging and perform an abort. I don't think this has been done before. During the Apollo program a special small rocket called "Little Joe" that used solid rocket motors took the Apollo spacecraft to enough height and speed where the test took place. More recently they just take off right from the ground (as with the Orion) and this test has already been performed on the Dragon."

"The motors used for abort on Dragon are built into the walls of the spacecraft rather than mounted on top and this is just one more step in the evolution of modern spacecraft."

"In looking at some of the pics above I notice they show a manned Dragon being launched by a Falcon Heavy. I'm not sure that is ever going to happen. In a way the Falcon 2.0 is already obsolete. The work on the BFR (or BFS) is now the main task taking place at SpaceX and it seems to be going well so far. If it works as expected then it will be a far safer and more reliable way of getting into space. The Falcon 2.0 will only be used until the big rocket is operational and that may be as soon as 2021 or 2022. To me this all seems to be happening at an incredible pace. It is very exciting and I have great confidence in the crew at SpaceX to get this job done."

Credit: Bill Davis
Release Date: June 17, 2018


#NASA #SpaceX #Space #ISS #Moon #Mars #Dragon #CrewDragon #Astronauts #Spacecraft #Falcon #Rocket #BFR #BFS #SolarSystem #Exploration #ElonMusk #JourneyToMars #Commercial #LaunchAmerica #KSC #UnitedStates #STEM #Education #Poster #Future #Colonization #Planet

Sunday, June 17, 2018

Martian Dust Storm | Hubble

What's happened to Mars? In 2001, Mars underwent a tremendous planet-wide dust storm—one of the largest ever recorded from Earth. To show the extent, these two Hubble Space Telescope storm watch images from late June and early September (2001) offer dramatically contrasting views of the martian surface. At left, the onset of smaller "seed" storms can be seen near the Hellas basin (lower right edge of Mars) and the northern polar cap. A similar surface view at right, taken over two months later, shows the fully developed extent of the obscuring global storm. Although this storm eventually waned, in recent days a new large dust storm has been taking hold of the red planet.

Image Credit: J. Bell (ASU), M. Wolff (Space Science Inst.), Hubble Heritage Team (STScI/AURA), NASA
Release Date: June 17, 2018


#NASA #Hubble #Space #Astronomy #Mars #RedPlanet #Planet #DustStorm #Telescope #ESA #Goddard #STScI #STEM #Education #APoD

Saturday, June 16, 2018

Inside NASA's Kennedy Space Center! | Week of June 15, 2018


This week in space news, a SpaceX Dragon cargo spacecraft will resupply the International Space Station with a launch from Cape Canaveral Air Force Station in Florida later this month. NASA's Ice, Cloud, and land Elevation Satellite-2, or ICESat-2, arrived at Vandenberg Air Force Base in California on Tuesday.

Credit: Kennedy Space Center (KSC)
Duration: 1 minute, 43 seconds
Release Date: June 15, 2018


#NASA #Space #Earth #ISS #SpaceX #Dragon #Cargo #Spacecraft #Earth #ICESat2 #ClimateChange #GlobalWarming #Environment #Kennedy #KSC #Florida #Spaceport #UnitedStates #STEM #Education #HD #Video
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