James Webb Space Telescope Archives

March 31, 2022April 2, 2022 by Matt Williams

New Simulation Recreates an Early Time in the Universe That Still Hasn't Been Seen Directly

The fields of astronomy and astrophysics are poised for a revolution in the coming years. Thanks to next-generation observatories like the James Webb Space Telescope (JWST), scientists will finally be able to witness the formation of the first stars and galaxies in the Universe. In effect, they will be able to pierce the veil of the Cosmic Dark Ages, which lasted from roughly 370,000 years to 1 billion years after the Big Bang.

During this period, the Universe was filled with clouds of neutral hydrogen and decoupled photons that were not visible to astronomers. In anticipation of what astronomers will see, researchers from the Harvard & Smithsonian Center for Astrophysics (CfA), the Massachusetts Institute of Technology (MIT), and the Max Planck Institute for Astrophysics (MPIA) created a new simulation suite called Thesan that simulates the earliest period of galaxy formation.

March 31, 2022March 31, 2022 by Evan Gough

It’s Not Conclusive, But Methane is Probably the Best Sign of Life on Exoplanets

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

When the James Webb Space Telescope aims at exoplanet atmospheres, it’ll use spectroscopy to identify chemical elements. One of the things it’s looking for is methane, a chemical compound that can indicate the presence of life.

Methane is a compelling biosignature. Finding a large amount of methane in an exoplanet’s atmosphere might be our most reliable indication that life’s at work there. There are abiotic sources of methane, but for the most part, methane comes from life.

But to understand methane as a potential biosignature, we need to understand it in a planetary context. A new research letter aims to do that.

March 29, 2022March 29, 2022 by Evan Gough

Part of the Milky Way Is Much Older Than Previously Believed

Basic structure of our home galaxy, edge-on view. The new results from ESA's Gaia mission provide for a reconstruction of the history of the Milky Way, in particular of the evolution of the so-called thick disc. Image Credit: Stefan Payne-Wardenaar / MPIA

The Milky Way is older than astronomers thought, or part of it is. A newly-published study shows that part of the disk is two billion years older than we thought. The region, called the thick disk, started forming only 0.8 billion years after the Big Bang.

March 19, 2022March 19, 2022 by Matt Williams

Machine Learning Will be one of the Best Ways to Identify Habitable Exoplanets

The field of extrasolar planet studies is undergoing a seismic shift. To date, 4,940 exoplanets have been confirmed in 3,711 planetary systems, with another 8,709 candidates awaiting confirmation. With so many planets available for study and improvements in telescope sensitivity and data analysis, the focus is transitioning from discovery to characterization. Instead of simply looking for more planets, astrobiologists will examine “potentially-habitable” worlds for potential “biosignatures.”

This refers to the chemical signatures associated with life and biological processes, one of the most important of which is water. As the only known solvent that life (as we know it) cannot exist, water is considered the divining rod for finding life. In a recent study, astrophysicists Dang Pham and Lisa Kaltenegger explain how future surveys (when combined with machine learning) could discern the presence of water, snow, and clouds on distant exoplanets.

March 19, 2022March 19, 2022 by Matt Williams

Wondering About the 6 Rays Coming out of JWST's Test Image? Here's why They Happen

At the Space Telescope Science Institute (STSI) in Baltimore, Maryland, NASA engineers are busy aligning the mirrors and instruments on the James Webb Space Telescope (JWST). In the meantime, the mission team has provided us with another glimpse of what this observatory – a successor to the venerable Hubble Space Telescope – will see once it is fully operational. The latest teaser is a “telescope alignment evaluation image” of a distant star that looks red and spiked!

March 17, 2022March 17, 2022 by Nancy Atkinson

ESA’s Gaia Just Took a Picture of L2 Neighbor JWST

Oh, hello there new neighbor! In February, the Gaia spacecraft took a picture of its new closest companion in space at the second Lagrangian point, the James Webb Space Telescope.

Gaia is an optical telescope that is mapping out our galaxy by surveying the motions of more than a thousand million stars. Astronomers for the mission realized that once JWST reached L2, it would be in Gaia’s field of view. It spied JWST when the two spacecraft were a million km apart.

March 16, 2022March 17, 2022 by Nancy Atkinson

Webb has Now Taken the Sharpest Image the Laws of Physics Allow

A JWST engineering image of the star 2MASS J17554042+6551277, uses a red filter to optimize visual contrast. Credits: NASA/STScI

Engineers and scientists for the James Webb Space Telescope have completed two more steps in the telescope’s primary mirror alignment process, and in a briefing today, officials said JWST’s optical performance appears to be better than even the most optimistic predictions.

The team released a new engineering image, showing the star 2MASS J17554042+6551277 in crisp clarity. This image demonstrates that all 18 mirror segments have been precisely aligned to act as one giant, high-precision 6.5-meter (21.3-foot) primary telescope mirror.

February 25, 2022February 26, 2022 by Nancy Atkinson

Webb turns those 18 separate star images into a single unified star. Next comes even better focus.

During this phase of alignment known as Image Stacking, individual segment images are moved so they fall precisely at the center of the field to produce one unified image instead of 18. In this image, all 18 segments are on top of each other. After future alignment steps, the image will be even sharper. Credit: NASA/STScI

It’s coming together! Engineers for the James Webb Space Telescope have now completed two more phases of the seven-step, three-month-long mirror alignment process. This week, the team made more adjustments to the mirror segments along with updating the alignment of its secondary mirror. These refinements allowed for all 18 mirror segments to work together — for the first time — to produce one unified image.

February 23, 2022April 8, 2022 by Nancy Atkinson

Here’s Exactly how Engineers Are Aligning JWST’s Segmented Mirrors

This early Webb alignment image, with dots of starlight arranged in a pattern similar to the honeycomb shape of the primary mirror, is called an “image array.” Credit: NASA/STScI/J. DePasquale

Engineers for the James Webb Space Telescope are in the midst of an intricate, three-month-long process of aligning the telescope’s 18 separate mirror segments to work together as one giant, high-precision 6.5-meter (21.3-foot) primary telescope mirror.

This process, called phasing, began in early February and includes seven different steps, which goes from taking the mirrors’ initial placements after they were deployed to doing a “coarse” and then “fine” alignment, and then making sure the mirror works with all four of Webb’s instruments and their various fields of view.

February 21, 2022February 21, 2022 by Scott Alan Johnston

James Webb Might be Able to Detect Other Civilizations by their Air Pollution

The James Webb Space Telescope (JWST), launched last December, has been slowly powering up its instruments and unfurling its sunshield, and is now in the process of aligning its mirrors in preparation for operation. Within a few months, the most powerful space telescope ever built is going to set its sights on the stars. Astronomers are hoping that what JWST sees will change the way we understand our universe, just as the Hubble Space Telescope did decades before.

One tantalizing capability that JWST offers that Hubble could not is the opportunity to directly image planets orbiting distant stars, and maybe, just maybe, detect signs of life.