From Jupiter to the Universe: First science targets chosen for James Webb Space Telescope

Artist’s conception of the James Webb Space Telescope in space. Image Credit: Northrop Grumman

The James Webb Space Telescope (JWST) may not be launching until 2019, but the first targets for the powerful new observatory have already been chosen, including Jupiter, organic molecules in star-forming clouds and baby galaxies in the distant Universe. JWST is the long-awaited “successor” to the Hubble Space Telescope and will provide unprecedented new views of the Universe.

These first targets were chosen from 100 different proposals as part of a competitive peer-review selection process and have been allotted nearly 500 hours of observing time.

“We were impressed by the high quality of the proposals received. These programmes will not only generate great science, but will also be a unique resource for demonstrating the investigative capabilities of this extraordinary observatory to the worldwide scientific community,” said Ken Sembach, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “We want the research community to be as scientifically productive as possible, as early as possible, which is why I am so pleased to be able to dedicate nearly 500 hours of director’s discretionary time to these early release science observations.”

Jupiter, as seen here recently by the Juno spacecraft, will be one of the first targets of JWST. Image Credit: NASA/SwRI/MSSS/Gerald Eichstädt/Seán Doran

One great aspect of these observations is that the data will be publicly available immediately, which will help astronomers plan follow-up observations, as well as, of course, benefitting the public in general.

Four of the first set of observations will be led by astronomers from ESA, while JWST itself is a collaboration of ESA, NASA and the Canadian Space Agency.

“It is exciting to see the engagement of the astronomical community in designing and proposing what will be the first scientific programmes for the James Webb Space Telescope,” noted Alvaro Gimenez, ESA Director of Science.

The Hubble Space Telescope already revolutionized our knowledge about the Universe, and now JWST will expand on that.

Engineers conducting a white light inspection of the James Webb Space Telescope’s large mirror. Photo Credit: NASA/Chris Gunn
Diagram depicting different parts of JWST. Image Credit: NASA

“Webb will revolutionise our understanding of the Universe and the results that will come out from these early observations will mark the beginning of a thrilling new adventure in astronomy,” said Gimenez.

JWST will search for the earliest galaxies in the Universe, and study the massive black holes at their centers, as well as observe the birth of new stars and planetary systems. As reported earlier, JWST will also look at Europa and Enceladus, two ocean moons in our Solar System which are thought to be able, maybe, to support some form of life.

One of the most exciting objectives of JWST is to analyze the atmospheres of some closer exoplanets, including to search for possible biomarkers as evidence of life. An increasing number of exoplanets which are near Earth-sized and/or in the habitable zones of their stars are being discovered by astronomers, and JWST will help to narrow down which ones are potentially the most habitable.

One of the most exciting tasks of JWST will be to examine some nearby exoplanets for possible signs of life in their atmospheres. Image Credit: NASA Ames/SETI Institute/JPL-Caltech

“I’m thrilled to see the list of astronomers’ most fascinating targets for the Webb telescope, and extremely eager to see the results. We fully expect to be surprised by what we find,” said John C. Mather, Senior Project Scientist for the Webb telescope and Senior Astrophysicist at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

JWST had been scheduled to launch in October 2018, but that date was pushed backed to spring 2019.

This article was first published on AmericaSpace.




Only 5 ring crossings left as Cassini nears end of historic mission at Saturn

Saturn’s moon Prometheus lurks near the outer F ring in this new view from Cassini. Photo Credit: NASA/JPL-Caltech/Space Science Institute

NASA’s Cassini spacecraft just completed its 17th ring crossing at Saturn, part of the Grand Finale phase of the mission, leaving only 5 more to go before the mission ends on Sept. 15. As before, the ring crossing was a success, with Cassini sending back precious more data about the Saturn system even though time is now running short. The ring crossings, bringing the spacecraft closer to Saturn than ever before, provide a unique way for scientists to learn even more about Saturn and its moons in a manner never before possible.

During each ring crossing, Cassini performs specific observations. For this particular one, these included:

  • Cassini’s Ultraviolet Imaging Spectrograph (UVIS) observed Saturn’s northern aurora, attempting to capture the entire auroral oval over several observations.
  • The spacecraft’s imaging cameras, the Imaging Science Subsystem (ISS), performed the first of two final observations of one of Saturn’s tiny, irregular moons, named Kiviuq, which completes about 80 percent of one rotation during Cassini’s observation. The observation is intended to improve models of the moon’s shape and other of Kiviuq’s characteristics.
  • The ISS instrument also targeted one of Saturn’s ring propeller features, and also continued its campaign of observing Saturn’s moon Titan for two segments of time, each lasting several hours, to image the moon’s atmosphere and surface, in particular to watch Titan’s clouds form and change. The spacecraft’s Composite Infrared Spectrometer (CIRS) and Visible and Infrared Mapping Spectrometer (VIMS) observed Titan as well.
  • Also during this orbit, the spacecraft rolled to calibrate Cassini’s magnetometer (MAG).
  • During this orbit, Cassini got within 1,830 miles (2,940 kilometers) of Saturn’s 1-bar level. Cassini also passed within 2,960 miles (4,760 kilometers) of the inner edge of Saturn’s D ring.
Recent spectacular image from Cassini showing Saturn’s shadow on the finely detailed rings. Photo Credit: NASA/JPL-Caltech/Space Science Institute
Another recent raw image showing an incredible amount of very fine detail in the rings, like the grooves on a vinyl record. Photo Credit: NASA/JPL-Caltech/Space Science Institute
Another close-up raw image view of Saturn’s rings taken by Cassini on June 4, 2017. Photo Credit: NASA/JPL-Caltech/Space Science Institute
Auroras at Saturn’s south pole, seen by Cassini on July 20, 2017. The bright specks and streaks appearing from frame to frame are due to charged particles and cosmic rays hitting the camera detector. Image Credit: NASA/JPL-Caltech/Space Science Institute
Saturn’s north polar “hexagon” jet stream is one of the most unusual features seen on any planet in the Solar System. Photo Credit: NASA/JPL-Caltech
Raw image view of Saturn’s largest moon Titan from July 31, 2017. One of the last views Cassini will see. Photo Credit: NASA/JPL-Caltech/Space Science Institute


Also during each ring crossing, Cassini has sent back incredible new images of Saturn and its moons. The views of Saturn and its rings are from a vantage point never before possible – between the planet itself and the innermost rings. The views have been spectacular, showing unprecedented detail in the structure of the rings and storms and clouds in the turbulent atmosphere. One new image posted yesterday shows the tiny moon Prometheus orbiting just inside the narrow F ring.

There is also new feature just posted, number 8, of Nine Ways Cassini Matters:

“Cassini represents a staggering achievement of human and technical complexity, finding innovative ways to use the spacecraft and its instruments, and paving the way for future missions to explore our Solar System.”

The sand may be running out of the hourglass, but Cassini will squeeze out every bit of science it can before the mission comes its fiery end.

All of Cassini’s raw images can be seen here on the mission website.

This article was first published on AmericaSpace.


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Artist’s conception of a large Earth-like exomoon orbiting a giant gaseous exoplanet. Image Credit: Avatar/20th Century Fox

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Ocean world: new proposed mission would search for evidence of life in Europa’s subsurface water ocean. Photo Credit: NASA/JPL/Ted Stryk

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