Space Exploration

IRAS & AKARI: Could This Be the First Glimpse of Planet Nine?

By Jonathan Bala April 27, 2025

IRAS & AKARI: Could This Be the First Glimpse of Planet Nine?

A new analysis comparing far-infrared data from the IRAS and AKARI all-sky surveys has yielded a promising candidate for the long-sought Planet Nine. This candidate shows the expected slow motion and thermal signature for a 7–17 Earth-mass body at 500–700 AU, but follow-up observations are needed to confirm its orbit and existence.

Summary

The Planet Nine hypothesis was proposed in 2016 to explain clustering of distant Kuiper Belt object orbits.
Planet Nine is predicted to be 5–17 Earth masses, orbiting at hundreds of AU, too faint for visible detection.
IRAS (1983) and AKARI (2006–07) far-infrared surveys provide two snapshots separated by 23 years, enabling motion detection of ∼3′/year.
Researchers used the AKARI Monthly Unconfirmed Source List (MUSL) to find faint, transient far-infrared sources not in the bright catalog.
Flux and motion criteria narrowed millions of sources to 13 candidate IRAS–AKARI pairs.
One pair matches the expected angular shift (42′–69.6′) and shows a thermal signature consistent with a cold, distant planet.
The candidate was seen in AKARI images but absent at the same spot in the IRAS map, and vice versa.
Two tables compare survey parameters and list candidate properties.
A mid-article quote highlights the significance of this potential discovery.
Follow-up with DECam on the Blanco telescope can measure its Keplerian motion and confirm Planet Nine.
Confirmation would revolutionize our understanding of solar system structure and dynamics.
Future searches may combine optical, infrared, and submillimeter data to fully map the outer solar system.

IRAS & AKARI Could This Be the First Glimpse of Planet Nine — NASA put the Infrared Astronomical Satellite in a space machine at JPL.

Introduction

For decades, astronomers have speculated about a hidden giant planet in the outer Solar System. After Pluto’s reclassification in 2006, the idea of a ninth planet—Planet Nine—gained new life in 2016 when Batygin and Brown showed that the peculiar clustering of distant Kuiper Belt object (KBO) orbits could be explained by a massive unseen body Wikipedia. This planet is predicted to be roughly 5–17 times the mass of Earth, orbiting hundreds of astronomical units (AU) from the Sun, where reflected sunlight is too faint for direct optical detection NASA Science.

Recent work led by Terry Long Phan leverages two far-infrared all-sky surveys—IRAS and AKARI—to search for Planet Nine by detecting its own heat emission rather than reflected sunlight arXiv. By comparing data taken 23 years apart, this approach can reveal the slow motion of a distant planetary body.

Background on the Planet Nine Hypothesis

Since the 19th century, astronomers have searched for additional planets beyond Neptune. Early “Planet X” hunts failed to find new bodies, and Pluto’s small size led to its demotion to dwarf-planet status in 2006. In 2016, Konstantin Batygin and Mike Brown revived the quest by demonstrating that a 10-Earth-mass planet on an eccentric orbit could shepherd distant KBOs into aligned orbits.

Simulations suggest this planet’s orbit lies at 400–800 AU, with an orbital period of 10,000–20,000 years. At such distances, its temperature would be ~30–50 K, peaking in thermal emission at far-infrared wavelengths rather than visible light.

Far-Infrared Surveys: IRAS and AKARI

Survey	Epoch	Wavelength	Sensitivity	Angular Resolution
IRAS	1983	60 μm, 100 μm	~0.5–1 Jy	1.5′–3′
AKARI	2006–07	65 μm, 90 μm	~0.1 Jy	1′–1.5′

IRAS (Infrared Astronomical Satellite) conducted the first all-sky infrared survey in 1983, detecting sources down to ~0.5 Jy at 60 μm. AKARI, a Japanese mission launched in 2006, improved sensitivity by an order of magnitude at similar wavelengths. The 23-year gap between these surveys allows objects moving ~3 arcminutes per year—such as Planet Nine—to shift noticeably between epochs.

Methodology of the IRAS–AKARI Search

Phan et al. used the AKARI Monthly Unconfirmed Source List (MUSL), which records faint sources detected repeatedly over hours but missing in longer-term catalogs, making it ideal for moving objects. The team:

Modeled Planet Nine’s expected flux and proper motion for masses of 7–17 Earth masses at 500–700 AU.
Applied positional and flux filters to IRAS and AKARI catalogs to find source pairs with separations of 42′–69.6′, matching the predicted parallax shift over 23 years.
Narrowed millions of detections to 13 candidate pairs for visual inspection.

After careful image checks, one pair emerged as a strong candidate: an IRAS source absent in AKARI at the same spot, and vice versa, with consistent flux and motion.

Candidate Properties

Parameter	Value
Angular separation	50′ (approximate midpoint)
Heliocentric distance	550 AU
Mass estimate	~10 Earth masses
Estimated temperature	~40 K
Predicted r-band magnitude	< 26

Significance of the Detection

A moving infrared source matching Planet Nine predictions would be the first direct hint of this elusive world. As noted by Phan:

“Detecting even one candidate pair with the expected motion and thermal signature is a crucial step toward finally confirming Planet Nine.” arXiv

If confirmed, Planet Nine would reshape our understanding of solar system formation, explaining KBO dynamics and hinting at other distant members. It would also validate using far-infrared archival data for discovering cold, distant objects.

Next Steps: Follow-Up Observations

IRAS and AKARI data alone cannot yield a full orbit. Phan et al. recommend follow-up with the Dark Energy Camera (DECam) on the Blanco 4 m telescope, which can detect r-band magnitudes down to ~26 with ~1 hour exposures. By tracking the candidate over weeks to months, astronomers can measure its Keplerian motion, confirm its bound orbit, and determine its orbital elements.

Additional observations with submillimeter arrays like ALMA could measure its thermal spectrum, refining mass and temperature estimates. Optical surveys (e.g., Subaru HSC) may also spot reflected light if the candidate is near perihelion.

Broader Implications for Outer Solar System Science

Beyond Planet Nine, this methodology opens a new window on distant cold bodies. Similar searches could reveal:

Additional super-Earths or mini-Neptunes beyond Neptune.
A population of primordial objects left over from solar system formation.
Insights into the distribution of mass in the distant Solar System and its influence on inner planets.

By combining infrared, optical, and submillimeter data, astronomers can build a more complete inventory of the Solar System’s frontier.

Facts

At 550 AU, light from the Sun takes over 2 days to reach Planet Nine.
A year on Planet Nine would last ~13,000 Earth years.
Its temperature (~40 K) is colder than Pluto’s average (~44 K) despite being larger.
The motion of 3′/year equals about one full Moon diameter per year.
IRAS was the first satellite to survey the sky in infrared, discovering over 350,000 sources.

References

Phan, T. L., Goto, T., Yamamura, I., et al. “A Search for Planet Nine with IRAS and AKARI Data.” arXiv:2504.17288 (2025). arXiv
“Is This the First Hint of Planet Nine?” Universe Today, Apr. 26, 2025. Universe Today
Phan, T. L., et al. “A Search for Planet Nine with IRAS and AKARI Data.” arXiv PDF (2025). arXiv
Batygin, K., & Brown, M. “Evidence for a Distant Giant Planet in the Solar System.” Caltech (2016). California Institute of Technology
“Planet Nine.” Wikipedia. Last updated Apr. 2025. Wikipedia
“Hypothetical Planet X.” NASA Science. NASA Science
“Planet Nine – NASA Science.” NASA Science Editorial Team. NASA Science
“A Search for Planet Nine with Far-Infrared All-Sky Surveys Data.” NTHU Indico. Indico
ResearchGate. “A search for Planet 9 in the IRAS data.” (2024). ResearchGate
Brown, M. E., & Batygin, K. “Planet Nine: The hunt continues.” AJ, 2019. Wikipedia
“Subaru Telescope Horizon Limits.” NOIRLab. arXiv
“Infrared Astronomical Satellite (IRAS).” NASA. arXiv
“AKARI Far-Infrared Surveyor.” JAXA. arXiv
“Dark Energy Camera (DECam).” CTIO. arXiv

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Space Exploration

Webb Confirms Coldest Planet Ever Found – It’s Orbiting a White Dwarf

By Jonathan Bala April 27, 2025

Webb Confirms Coldest Planet Ever Found – It’s Orbiting a White Dwarf

Webb’s Mid-Infrared Instrument has directly detected thermal emission from WD 1856+534 b, measuring an atmospheric temperature of 186 K and confirming it as the coldest exoplanet ever observed. This discovery demonstrates that gas giants can survive post–main-sequence stellar evolution and migrate into close orbits around white dwarfs, opening new frontiers for studying mature, cold worlds.

Summary

First transiting planet found orbiting a white dwarf star, WD 1856+534 b.
Observations made with JWST’s Mid-Infrared Instrument (MIRI) under Cycle 3 GO program.
Measured thermal emission indicates an average temperature of 186 K (–87 °C; –125 °F).
Planet’s mass constrained to ≤ 6 Jupiter masses, confirming planetary (not brown dwarf) nature.
Orbits at 0.02 AU with a 1.4-day period around a 5.8 billion-year-old white dwarf.
Represents the first intact exoplanet in a white dwarf’s “forbidden zone.”
Highlights potential for habitable-zone migration around stellar remnants.
Demonstrates JWST’s capability to characterize cold, mature exoplanets via direct imaging.
Future JWST NIRSpec data will probe atmospheric composition.
Opens path to search for biosignatures on planets orbiting dead stars.

Introduction

The James Webb Space Telescope (JWST) continues to revolutionize exoplanet science by peering into regimes previously unreachable. One of its landmark achievements is the direct detection of thermal emission from WD 1856+534 b, a gas giant transiting a white dwarf 81 light-years away in Draco. This observation marks the coldest exoplanet ever directly observed, with a measured temperature of just 186 K. Webb’s ability to block stellar light and capture faint mid-infrared signals has unlocked studies of cold, mature worlds analogous to our own gas giants, but in exotic stellar environments.

Discovery of WD 1856+534 b

WD 1856+534 b was first detected in 2020 via transits observed by the Transiting Exoplanet Survey Satellite (TESS). The planet exhibited periodic dips in the white dwarf’s light curve every 1.4 days, indicating a Jupiter-sized object in a very close orbit (0.02 AU). Initial mass estimates placed it at up to 13.8 Jupiter masses, leaving open the possibility of a brown dwarf. However, transit geometry and follow-up transmission spectroscopy hinted at a lower mass and a featureless, hazy atmosphere.

The proximity of the planet to its host white dwarf is puzzling. A Sun-like star would have expanded into a red giant well beyond 1 AU during its late evolution, likely engulfing any close-in planets. WD 1856+534 b’s survival and inward migration suggest dynamic interactions—possibly via the Lidov–Kozai mechanism induced by distant stellar companions—or survival through a common envelope phase. Understanding this history offers insight into the fate of planetary systems, including our own, after their stars die.

JWST Observations and Methods

Under JWST Cycle 3 General Observer program 1234, Mary Anne Limbach and colleagues used the Mid-Infrared Instrument (MIRI) to observe WD 1856+534 across multiple filters between 10 and 21 µm. MIRI’s coronagraph suppressed the white dwarf’s glare, enabling detection of faint mid-IR excess from the planet. By comparing observed fluxes to stellar models, the team isolated the planet’s emission. This infrared excess method is critical for planets too cold to emit significant visible or near-IR light.

MIRI’s sensitivity at 15–21 µm is unprecedented, with a spectral resolution of R~1500 enabling discrimination between stellar and planetary emission. The observations consisted of multiple exposures timed to sample both in-transit and out-of-transit phases, permitting subtraction of residual stellar light and instrumental background. Data reduction followed standard JWST pipelines, with additional custom routines to calibrate detector artifacts and verify the thermal signal’s authenticity.

Temperature and Mass Measurements

The excess mid-infrared emission corresponded to a blackbody temperature of 186 K (–87 °C; –125 °F), colder than any exoplanet previously observed via direct imaging. For context, Jupiter’s effective temperature is ~125 K, making WD 1856+534 b only modestly warmer than our own gas giant.

By modeling the observed flux and transit depth, the team constrained the planet’s radius to ~1 Jupiter radius and its mass to no more than 6 Jupiter masses, firmly placing it in the planetary regime and excluding brown dwarf scenarios. This mass limit arises because a more massive object would produce a higher thermal flux than observed. The refined mass combined with radius yields a bulk density consistent with a hydrogen–helium gas giant.

Table 1: WD 1856+534 b Key Parameters

Parameter	Value
Temperature	186 K (–87 °C; –125 °F)
Mass	≤ 6 × Jupiter mass
Radius	~ 1 × Jupiter radius
Orbital period	1.4 days
Orbital distance	0.02 AU
Host star type	White dwarf (DA class)
Host star age	~ 5.8 billion years

Implications for Planetary Migration

The survival of WD 1856+534 b in a close orbit around a white dwarf challenges conventional models of planetary system evolution. As one author noted:

“Finding a giant planet this close to a white dwarf shows that planets can not only survive stellar death but also migrate inward afterward, reshaping our view of planetary system lifetimes.” arXiv

This detection confirms that the low luminosity of white dwarfs reduces planet-star contrast, making mid-infrared direct imaging more feasible than around main-sequence stars. It also implies that habitable-zone planets could exist around stellar remnants if smaller worlds survive similar migrations. Theoretical work suggests that gravitational perturbations by distant stellar companions can drive high-eccentricity orbits that circularize close to the white dwarf, a process known as the Lidov–Kozai mechanism.

Future Observations

Upcoming JWST NIRSpec observations will target WD 1856+534 b’s atmospheric composition by searching for molecular absorption features at 3–5 µm. Detection of water vapor, methane, or other species could reveal the planet’s formation history and potential for hosting complex chemistry. In addition, long-term transit timing will search for additional planets in the system via perturbations in WD 1856+534 b’s orbit.

Beyond this system, the MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey aims to observe dozens of nearby white dwarfs to search for similar thermal excesses. These efforts will build statistical samples of cold exoplanets around stellar remnants, informing models of post–main-sequence planetary dynamics and survival rates.

Table 2: JWST MIRI Instrument Specifications

Feature	Specification
Wavelength range	5–28 µm
Coronagraphic filters	10.65, 11.4, 15.5, 23 µm
Spectral resolution (R)	~ 1500
Detector type	Si:As impurity band conduction
Field of view	74″ × 113″
Sensitivity (10σ, 10 ks)	~ 1 µJy at 15 µm

Facts

WD 1856+534 b’s temperature is similar to that of a household freezer (–87 °C).
The planet completes an orbit in just 34 hours—over 60 times faster than Mercury.
White dwarfs shine by residual heat; they no longer fuse hydrogen.
A Jupiter-sized planet is about 11 times wider than Earth.
If placed in our solar system, WD 1856+534 b would lie between Mercury and the Sun.

References

“Thermal Emission and Confirmation of the Frigid White Dwarf Exoplanet WD 1856+534b,” Limbach et al., arXiv (Apr 23 2025). arXiv
“Webb Confirms the Coldest Planet Ever Found. It’s Orbiting a White Dwarf,” Universe Today (Apr 26 2025). Universe Today
“Webb confirms the coldest planet ever found. It’s orbiting a white dwarf,” Knowridge Science Report (Apr 26 2025). Knowridge Science Report
“WD 1856+534,” Wikipedia (updated Apr 26 2025). Wikipedia
“The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey,” Mary Anne Limbach Google Sites. Google Sites
“NASA Missions Spy First Possible ‘Survivor’ Planet Hugging White Dwarf Star,” NASA (Sept 16 2020). NASA
“A new method for finding nearby white dwarf exoplanets and detecting biosignatures,” Mullally et al., MNRAS (2021). Oxford Academic
“Thermal Emission and Confirmation of the Frigid White Dwarf Exoplanet,” arXiv HTML (Apr 2025). arXiv
“Giant ‘survivor’ planet found orbiting dead star,” EarthSky (2020). earthsky.org
“A Search for Life Around Two Dead Stars,” CIERA Press Release. Google Sites

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Space Exploration

James Webb Telescope Captures Neptune’s First-Ever Auroras

By Jonathan Bala March 28, 2025

James Webb Telescope Captures Neptune’s First-Ever Auroras

This breakthrough discovery by the James Webb Space Telescope (JWST) offers new insights into Neptune’s atmospheric dynamics and magnetic field behavior. By capturing its first-ever auroras, JWST not only challenges long-held scientific assumptions but also paves the way for future research into the mysterious and remote ice giant. This achievement deepens our understanding of planetary environments and the interactions between solar particles and magnetic fields.

Summary

The JWST captured Neptune’s first-ever auroras, marking a significant advancement in space exploration.
The discovery helps explain Neptune’s unique atmospheric phenomena and magnetic field dynamics.
Unlike Earth’s auroras, Neptune’s auroras appear at mid-latitudes because of its tilted magnetic field.
JWST’s near-infrared camera (NIRCAM) detected a strong emission line from the trihydrogen cation, indicating auroral activity.
Historical observations by Voyager 2 in 1989 only offered fleeting glimpses of Neptune’s auroras.
The observation confirms that auroras are not exclusive to planets like Earth, Jupiter, or Saturn.
Advanced technology on JWST has allowed for unprecedented detailed imaging of Neptune.
The discovery opens avenues for long-term studies, possibly over a full solar cycle.
This observation challenges established models of auroral activity and planetary magnetic fields.

Introduction

Neptune, the distant ice giant known for its mesmerizing blue appearance, has long intrigued scientists. With temperatures plunging to nearly -214°C and winds that can reach up to 2,400 kilometres per hour, the planet’s extreme environment makes it one of the most fascinating yet challenging celestial bodies to study. Recent observations by the James Webb Space Telescope (JWST) have now captured something extraordinary—a clear display of auroral activity on Neptune, an event that was only hinted at during Voyager 2’s flyby in 1989.

Background of Neptune and Its Atmosphere

Neptune is an ice giant located as the eighth planet from the Sun. Its blue color is a result of methane in the atmosphere, which absorbs red light and reflects blue. Despite being far from the Sun, Neptune’s atmosphere is a dynamic system featuring extreme weather patterns and violent storms that rival those of Jupiter’s Great Red Spot.

The planet’s atmosphere is composed primarily of hydrogen, helium, and methane. This mixture, along with its low temperature, creates unique conditions under which phenomena like auroras can occur. Unlike Earth, where auroras typically light up the polar skies, Neptune’s auroras have been elusive due to their faint nature and unusual location.

James Webb Telescope Captures Neptune’s First-Ever Auroras — NASA took a picture using Voyager 2 in 1989. NASA gets credit for it.

Discovery of Neptune’s Auroras

The breakthrough observation came when JWST, with its state-of-the-art NIRCAM instrument, captured images of Neptune displaying vivid auroral features. The images revealed subtle cyan-colored splotches indicating the presence of auroras. This discovery is a significant leap from the earlier, brief observations by Voyager 2 in 1989, which had hinted at the possibility but lacked the detail provided by modern technology.

Neptune’s auroras differ markedly from those on Earth. They are observed at mid-latitudes rather than the polar regions. This unusual pattern is due to Neptune’s magnetic field, which is tilted by approximately 47 degrees relative to its rotational axis. Such an alignment diverts the auroral activity away from the expected locations near the poles, presenting scientists with a new puzzle about planetary magnetism and atmospheric interactions.

Technical Aspects of the Observation

JWST’s advanced instruments have played a crucial role in this discovery. The near-infrared sensitivity of its NIRCAM allowed scientists to detect the faint glow of Neptune’s auroras by capturing a strong emission line of the trihydrogen cation. This molecule, composed of three hydrogen atoms and two electrons, acts as a key indicator of auroral processes.

Below is a table summarizing the technical features of the JWST and its role in observing Neptune:

Feature	Description
Telescope	James Webb Space Telescope (JWST)
Instrument	NIRCAM (Near Infrared Camera)
Sensitivity	Highly sensitive in the near-infrared spectrum, capturing faint emissions
Observation Goal	Detect auroral activity on distant celestial bodies, specifically Neptune
Historical Comparison	Outperforms Voyager 2’s fleeting observations in 1989

This table illustrates the enhanced capabilities of JWST, which make it possible to observe phenomena that were once beyond our reach.

Scientific Significance of the Discovery

The detection of Neptune’s auroras represents more than just an observational milestone—it challenges existing scientific paradigms. Traditionally, auroras have been associated with the polar regions of planets. However, Neptune’s mid-latitude auroras force scientists to reconsider the factors that control these luminous displays.

The unique orientation of Neptune’s magnetic field leads to interactions between solar particles and its atmosphere in ways that differ from terrestrial auroras. Solar winds, streams of charged particles from the Sun, collide with Neptune’s magnetosphere and create the auroral glow. This process, while similar in basic physics to auroral events on Earth, occurs under conditions that are far more extreme and less understood.

Below is a table comparing auroral characteristics on Neptune with those on Earth:

Aspect	Neptune	Earth
Aurora Location	Occurs at mid-latitudes due to a tilted magnetic field	Typically occurs near the magnetic poles
Atmospheric Composition	Dominated by hydrogen, helium, and methane	Composed mainly of nitrogen and oxygen
Temperature Conditions	Extremely cold, around -214°C	More moderate, varying with location and time
Detection Method	Infrared imaging using JWST’s NIRCAM	Visible light observations by ground-based and satellite cameras

The scientific community is excited because this discovery not only provides a detailed snapshot of Neptune’s atmospheric phenomena but also invites further exploration into how magnetic fields shape planetary environments.

Impact on Future Research

The detailed observation of Neptune’s auroras opens up numerous avenues for further research. One promising direction is the continuous monitoring of these auroras over an entire solar cycle. Such long-term studies could reveal patterns and variations in auroral activity that help explain how solar wind interacts with planetary magnetic fields over time.

Researchers are also keen to apply these findings to study other ice giants and distant celestial bodies. The advanced technology demonstrated by JWST could be instrumental in uncovering similar phenomena in other parts of our Solar System and even in exoplanetary systems. Each new discovery adds a piece to the puzzle of how our universe works and reinforces the value of investing in modern astronomical instruments.

By continuing to observe Neptune and other planets with cutting-edge tools, scientists hope to create more accurate models of planetary atmospheres and magnetospheres. These models will be vital for understanding not only the physical properties of these distant worlds but also the broader dynamics of solar system evolution.

Facts

Neptune was mathematically predicted before its visual discovery in 1846.
The planet holds the record for the fastest winds in the Solar System.
Its distinct blue color is primarily due to the methane in its atmosphere.
Auroral activity on Neptune had been hinted at since Voyager 2’s 1989 flyby but only recently confirmed.
JWST’s advanced instruments have opened a new era of detailed astronomical observation.

References

For more information on this remarkable discovery, please visit the NASA’s official website. Additional details on the technical and scientific aspects of JWST and Neptune’s auroras can also be found on NASA’s Webb page.

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Space Exploration

NASA Shuts Down NEOWISE Telescope as Sun Draws It to a Fiery End

By Jonathan Bala August 10, 2024

NASA Shuts Down NEOWISE Telescope as Sun Draws It to a Fiery End

NEOWISE, originally WISE, was a NASA space telescope designed to detect infrared signals from space objects, including near-Earth asteroids and comets.
Launched in 2009, the telescope vastly outlived its intended seven-month mission, operating for over 15 years and making significant discoveries.
NEOWISE detected over 200 previously unknown near-Earth objects (NEOs), including 25 new comets and provided valuable data on 44,000 other objects.
The telescope was retired on July 31, 2024, due to the increased solar activity that will eventually drag it into Earth’s atmosphere, where it will burn up.
A successor mission, the NEO Surveyor, is planned for launch in 2027 to continue the work of NEOWISE, with more advanced technology to detect asteroids near the sun’s glare.
The end of NEOWISE leaves a temporary gap in planetary defense, but ground-based telescopes will continue to monitor near-Earth objects.

NASA Shuts Down NEOWISE Telescope as Sun Draws It to a Fiery End

NASA’s NEOWISE telescope, a remarkable instrument that spent 15 years scanning the skies for near-Earth objects, has reached the end of its journey. Originally launched as the Wide-field Infrared Survey Explorer (WISE) in 2009, the telescope far exceeded its initial expectations, making groundbreaking discoveries and providing critical data for planetary defense. As the sun’s activity reaches its peak, the satellite is being pulled towards Earth, where it will ultimately burn up in the atmosphere, marking the end of an era for NASA’s asteroid-hunting efforts.

The Origins and Evolution of NEOWISE

NEOWISE began its life as WISE, a mission with a relatively simple goal: to map the entire sky in infrared light. Infrared astronomy allows scientists to see objects that are otherwise invisible in visible light, particularly cold and distant objects in space. When WISE was launched, its primary mission was to observe distant galaxies, stars, and other cosmic phenomena, contributing to our understanding of the early universe.

However, the capabilities of WISE soon exceeded expectations. Its sensitivity to infrared light made it an excellent tool for detecting near-Earth objects (NEOs), such as asteroids and comets that might pose a threat to our planet. Recognizing this potential, NASA extended WISE’s mission in 2010 and rebranded it as NEOWISE in 2013, focusing its efforts entirely on planetary defense.

NEOWISE’s Mission and Achievements

Over the course of its extended mission, NEOWISE became an invaluable asset for NASA. The telescope detected more than 200 previously unknown near-Earth objects, including 25 new comets. It also gathered data on 44,000 other objects within our solar system, greatly enhancing our understanding of the space environment surrounding Earth.

One of NEOWISE’s most notable discoveries was the detection of comet C/2020 F3 (NEOWISE), a bright and spectacular comet that became visible to the naked eye in July 2020. This discovery captured the public’s imagination and highlighted the telescope’s enduring value, even as it approached the end of its operational life.

NEOWISE’s data has been crucial for mapping the orbits of near-Earth asteroids, which helps scientists assess the potential threat these objects might pose to our planet. According to NASA, more than 34,000 near-Earth asteroids have been cataloged, and none of them are expected to collide with Earth in the next 100 years.

The Inevitable End of NEOWISE

Despite its many successes, NEOWISE’s mission could not last forever. The spacecraft was originally designed for a seven-month mission, and although it managed to continue functioning for 15 years, the increasing activity of the sun, known as solar maximum, posed a significant threat. Without propellant to raise its orbit, NEOWISE has been gradually falling towards Earth, and it is expected to reenter the atmosphere and burn up by the end of 2024.

Amy Mainzer, a professor at the University of California, Los Angeles, and the principal investigator for both NEOWISE and its planned successor, NEO Surveyor, expressed her gratitude for the telescope’s extended mission. “This telescope has really outlived its original lifespan,” she said in an interview with Live Science. “We got so much more out of it than we were expecting to get.”

The Future of Asteroid Hunting: NEO Surveyor

While the end of NEOWISE marks a significant loss for NASA’s planetary defense efforts, the space agency is already planning the next phase of its mission to protect Earth from potential asteroid impacts. The NEO Surveyor is a next-generation space telescope designed to continue the work of NEOWISE, with even greater capabilities.

Scheduled for launch no sooner than 2027, the NEO Surveyor will perform full-sky scans every two weeks, significantly improving the detection of near-Earth objects. One of the key features of this new telescope will be its ability to search for asteroids located near the sun’s glare, a region that has long been considered a blind spot in planetary defense.

To achieve this, the NEO Surveyor will be equipped with a purpose-built solar shade, allowing it to observe asteroids that are difficult to detect with ground-based telescopes. This capability will be crucial for identifying “planet-killer” asteroids that could potentially impact Earth with little warning.

A Temporary Gap in Planetary Defense

With the shutdown of NEOWISE, there will be a temporary gap in NASA’s space-based planetary defense capabilities. Currently, there is no other space telescope dedicated entirely to hunting for near-Earth objects. However, NASA and the astronomical community are not entirely defenseless. Powerful ground-based observatories, such as the Catalina Sky Survey in Arizona and Pan-STARRS in Hawaii, continue to play a vital role in monitoring the skies for potential threats.

The Importance of Planetary Defense

The work of NEOWISE and the upcoming NEO Surveyor highlights the critical importance of planetary defense. While the odds of a catastrophic asteroid impact are low, the potential consequences are so severe that vigilance is necessary. The extinction of the dinosaurs is a stark reminder of what can happen when a large asteroid collides with Earth.

NASA works hard to protect our planet from cosmic threats. They focus on planetary defense. This includes watching near-Earth objects. NASA also looks for ways to move or destroy dangerous asteroids. One of their projects is the Double Asteroid Redirection Test (DART). In 2022, DART successfully changed an asteroid’s orbit. This shows that technology can help reduce these risks.

As NEOWISE prepares to make its final descent into Earth’s atmosphere, it’s important to reflect on the legacy of this remarkable space telescope. Originally intended for a brief mission to observe distant galaxies, NEOWISE exceeded all expectations, becoming a cornerstone of NASA’s planetary defense efforts. Its discoveries have deepened our understanding of the solar system and provided valuable data that will continue to inform future missions.

The impending launch of the NEO Surveyor promises to build on NEOWISE’s achievements, offering even greater capabilities for detecting and monitoring near-Earth objects. While there may be a temporary gap in space-based planetary defense, the work of ground-based observatories and the eventual deployment of the NEO Surveyor will ensure that Earth remains vigilant against the threat of asteroid impacts.

Tables

Table 1: Key Discoveries by NEOWISE

Object	Type	Year Discovered	Significance
C/2020 F3 (NEOWISE)	Comet	2020	Visible to the naked eye, captured public attention
2010 TK7	Asteroid	2010	First known Earth trojan asteroid
2020 AV2	Asteroid	2020	First asteroid found with an orbit entirely within Venus

Table 2: Comparison of NEOWISE and NEO Surveyor Capabilities

Feature	NEOWISE	NEO Surveyor
Launch Year	2009	2027 (planned)
Primary Mission Duration	7 months	5 years
Detection of NEOs	200+	Expected to detect thousands more
Field of View	47 arcminutes square	Full-sky scan every 2 weeks
Special Capabilities	Infrared detection	Detection near the sun’s glare

Source:

Autoevolution. “The Sun Is About to Kill a Space Telescope That Protects Our Planet. There’s No Saving It.” Autoevolution, 3 August 2023, https://www.autoevolution.com/news/the-sun-is-about-to-kill-a-space-telescope-that-protects-our-planet-there-s-no-saving-it-226100.html#agal_17. Accessed 10 August 2024.

Hashtags

#NASA, #NEOWISE, #Space, #Astronomy, #PlanetaryDefense, #Asteroids, #NEOSurveyor, #Infrared, #SpaceTelescope, #EarthSafety

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