NASA’s Says Goodbye to its Asteroid-Hunting NEOWISE Mission

NEOWISE
NEOWISE on the hunt. Credit: NASA/JPL

NASA’s Wide-field Infrared Survey Explorer (WISE), launched in 2009, spent the next fourteen and half years studying the Universe in infrared wavelengths. During that time, it discovered thousands of minor planets, star clusters, and the first Brown Dwarf and Earth-Trojan asteroid. By 2013, the mission was reactivated by NASA as the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), which was tasked with searching for Potentially Hazardous Asteroids (PHAs). For ten years, the NEOWISE mission faithfully cataloged comets and asteroids that could pose a threat to Earth someday.

Unfortunately, NASA announced on July 1st that it would be decommissioning this planetary defense mission, which is expected to burn up in our atmosphere later this year. On Thursday, August 8th, the mission was decommissioned after the final command was sent from NASA’s Jet Propulsion Laboratory in Southern California and related to the spacecraft by the Tracking and Data Relay Satellite (TDRS) system. However, the scientific data NEOWISE collected during its ten years of operation will continue to inspire new discoveries!

Continue reading “NASA’s Says Goodbye to its Asteroid-Hunting NEOWISE Mission”

Astronomers Propose a 14-Meter Infrared Space Telescope

An artist's illustration of the SALTUS Observatory concept. SALTUS is a Far-IR space telescope that will open a new window into the cosmos. Image Credit: NASA

The Universe wants us to understand its origins. Every second of every day, it sends us a multitude of signals, each one a clue to a different aspect of the cosmos. But the Universe is the original Trickster, and its multitude of signals is an almost unrecognizable cacophony of light, warped, shifted, and stretched during its long journey through the expanding Universe.

Continue reading “Astronomers Propose a 14-Meter Infrared Space Telescope”

Webb Sees a Galaxy Awash in Star Formation

Starburst galaxy M82 was observed by the Hubble Space Telescope in 2006, which showed the galaxy’s edge-on spiral disk, shredded clouds, and hot hydrogen gas. The James Webb Space Telescope has observed M82’s core, capturing in unprecedented detail the structure of the galactic wind and characterizing individual stars and star clusters. Credit: NASA/ESA/CSA/STScI/Alberto Bolatto (UMD)

Since it began operations in July 2022, the James Webb Space Telescope (JWST) has fulfilled many scientific objectives. In addition to probing the depths of the Universe in search of galaxies that formed shortly after the Big Bang, it has also provided the clearest and most detailed images of nearby galaxies. In the process, Webb has provided new insight into the processes through which galaxies form and evolve over billions of years. This includes galaxies like Messier 82 (M82), a “starburst galaxy” located about 12 million light-years away in the constellation Ursa Major.

Also known as the “Cigar Galaxy” because of its distinctive shape, M82 is a rather compact galaxy with a very high star formation rate. Roughly five times that of the Milky Way, this is why the core region of M82 is over 100 times as bright as the Milky Way’s. Combined with the gas and dust that naturally obscures visible light, this makes examining M82’s core region difficult. Using the extreme sensitivity of Webb‘s Near-Infrared Camera (NIRCam), a team led by the University of Maryland observed the central region of this starburst galaxy to examine the physical conditions that give rise to new stars.

Continue reading “Webb Sees a Galaxy Awash in Star Formation”

A Solo Brown Dwarf Found With Auroras

This artist concept portrays the brown dwarf W1935, which is located 47 light-years from Earth. Astronomers using NASA’s James Webb Space Telescope found infrared emission from methane coming from W1935, generating an aurora, a very unexpected discovery. Credit: NASA, ESA, CSA, Leah Hustak (STScI)

Astronomers have used JWST to find a brown dwarf with polar auroras like the Earth, or Jupiter. This is surprising because the brown dwarf, dubbed W1935, is a free-floating object, meaning it isn’t part of another star system. Therefore, there’s no solar wind available to generate any Northern Lights. Instead, the auroras are seemingly generated from methane emissions in the planet’s atmosphere, interacting with the interstellar plasma. Another theory is that it perhaps has an active but unseen moon contributing to the emissions.

Continue reading “A Solo Brown Dwarf Found With Auroras”

Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?

Obtaining accurate redshift measurements is a challenge, even with telescopes like Webb. Credit: NASA

One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its light has been traveling through space.

This is the purpose of the Cosmic Evolution Early Release Science Survey (CEERS), a collaborative research group that analyzes Webb data to learn more about galactic evolution. These galaxies are known as “high-redshift,” meaning that their light emissions are redshifted all the way into the infrared spectrum. Galaxies that existed ca. 13 billion years ago can only be observed in the near-infrared spectrum, which is now possible thanks to Webb’s Near-Infrared Camera (NIRCam). Even so, obtaining accurate redshift measurements from such distant galaxies is a very tricky, and requires advanced techniques.

Continue reading “Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?”

JWST Reveals a Newly-Forming Double Protostar

This new Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope reveals intricate details of the Herbig Haro object 797 (HH 797). HH 797 dominates the lower half of this image. The bright infrared objects in the upper portion of the image are thought to host two further protostars. This image was captured with Webb’s Near-InfraRed Camera (NIRCam). Image Credit: JWST/CSA/ESA/NASA

As our newest, most perceptive eye on the ongoing unfolding of the cosmos, the James Webb Space Telescope is revealing many things that were previously unseeable. One of the space telescope’s science goals is to expand our understanding of how stars form. The JWST has the power to see into the cocoons of gas and dust that hide young protostars.

It peered inside one of these cocoons and showed us that what we thought was a single star is actually a binary star.

Continue reading “JWST Reveals a Newly-Forming Double Protostar”

JWST Sees Four Exoplanets in a Single System

This artist’s rendering shows the star HR 8799 and one of its four planets, HR 8799c. It illustrates the system at an early stage of evolution. It also shows the star's dusty disk and rocky inner planets. Credit: Dunlap Institute for Astronomy & Astrophysics

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

Continue reading “JWST Sees Four Exoplanets in a Single System”

We Should Be Looking for Small, Hot Dyson Spheres

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

In 1960, legendary physicist Freeman Dyson published his seminal paper “Search for Artificial Stellar Sources of Infrared Radiation,” wherein he proposed that there could be extraterrestrial civilizations so advanced that they could build megastructures large enough to enclose their parent star. He also indicated that these “Dyson Spheres,” as they came to be known, could be detected based on the “waste heat” they emitted at mid-infrared wavelengths. To this day, infrared signatures are considered a viable technosignature in the Search for Extraterrestrial Intelligence (SETI).

So far, efforts to detect Dyson Spheres (and variation thereof) by their “waste heat” signatures have come up empty, leading some scientists to recommend tweaking the search parameters. In a new paper, astronomy and astrophysics Professor Jason T. Wright of the Center for Exoplanets and Habitable Worlds and the Penn State Extraterrestrial Intelligence Center (PSTI) recommends that SETI researchers refine the search by looking for indications of activity. In other words, he recommends looking for Dyson Spheres based on what they could be used for rather than just heat signatures.

Continue reading “We Should Be Looking for Small, Hot Dyson Spheres”

The Seasons on Saturn are Changing. It's Time to Say Goodbye to Its North Pole for a Few Years

Saturn, as seen by the James Webb Space Telescope's MIRI instrument, showing various portions of the planet's atmosphere. superimposed on an full image taken by the Hubble Space Telescope. Credit: NASA/ESA/Univ. Leicester/L.N. Fletcher/O. King

Just like Earth, Saturn goes through seasons because of its axial tilt. But a year on Saturn lasts 30 Earth years, so each of its seasons lasts 7.5 years. Right now, it is late summer on Saturn’s northern hemisphere, so again, just like Earth is currently heading for northern autumn equinox in September, Saturn is heading for northern autumn equinox a little later, in 2025.

Before Saturn’s north pole enters its extended polar winter – rendering it inaccessible for observations — astronomers are taking advantage of being able to study this area with the James Webb Space Telescope, which became operational just over a year ago.

Continue reading “The Seasons on Saturn are Changing. It's Time to Say Goodbye to Its North Pole for a Few Years”

Twinkling Stars Supply the Dust That Leads to Life

Artist’s impression of the star in its multi-million year long and previously unobservable phase as a large, red supergiant. Credit: CAASTRO / Mats Björklund (Magipics)

When low to medium-mass stars exhaust their supply of hydrogen, they exit their main sequence phase and expand to become red giants – what is known as the Asymptotic Giant Branch (AGB) phase. Stars in this phase of their evolution become variable (experiences changes in brightness) to shed their outer lays, spreading dust throughout the interstellar medium (ISM) that is crucial to the development of planetary nebulas and protoplanetary systems. For decades, astronomers have sought to better understand the role Red Giant stars play.

Studying interstellar and protoplanetary dust is difficult because it is so faint in visible light. Luckily, this dust absorbs light and radiates brightly in the infrared (IR), making it visible to IR telescopes. Using archival data from now-retired Akari and Wide-field Infrared Survey Explorer (WISE) missions, a team of Japanese astronomers conducted the first long-period survey of dusty AGBs and observed that the variable intensity of these stars coincides with the amount of dust they produce. Since this dust plays an important role in the formation of planets, this study could shed light on the origins of life.

Continue reading “Twinkling Stars Supply the Dust That Leads to Life”