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Source: www.war.gov
Arctic Melt Season Length Levels Off
2000-2009
2010-2023
NASA Earth Observatory/Michala Garrison
NASA Earth Observatory/Michala Garrison
NASA Earth Observatory/Michala Garrison
NASA Earth Observatory/Michala Garrison
2000-2009
2010-2023
Since the start of the satellite record, the Arctic sea ice melt season has lengthened in most decades, particularly in the 2000s (left). Since 2010 (right), the melt season appears to have stabilized. NASA Earth Observatory images by Michala Garrison based on data from Boisvert, L., et al.
For decades, Arctic sea ice has been melting earlier in spring and freezing later in fall, extending the melt season and contributing to widespread ice loss. A new NASA-led study has found that while the Arctic melt season has lengthened dramatically since satellite records began, that trend unexpectedly stabilized around 2010.
The Arctic sea ice melt season is now about 40 days longer than it was in 1979, according to the study. Most of the increase occurred before 2010. Since then, the average melt season length has remained relatively unchanged, despite large year-to-year fluctuations.
Researchers analyzed satellite observations between 1979 and 2023 to track when sea ice begins to melt each spring and refreezes each autumn. They found that the change was driven primarily by sea ice freezing later in the year rather than melting earlier in the spring.
“Previously, there was more of this multiyear ice that didn’t melt away each summer,” said Linette Boisvert, a co-author on the study and ice scientist at NASA’s Goddard Space Flight Center. “Now that the ice is thinner and there’s less of it, there’s a lot more variability.” On average, though, the decline in sea ice thickness and extent that occurred during the 2000s appears to have stopped for the time being.
To understand why, the team examined changes in the Arctic’s energy balance—the net difference between incoming heat from the Sun, atmosphere, and ocean and the outgoing infrared radiation emitted back to space.
During the period of rapid ice loss in the 2000s, reduced ice cover exposed darker ocean water, which absorbed more sunlight. The additional solar energy delayed freezing and helped extend the melt season. In the left map above, the reddest areas mark where the melt season grew fastest that decade, by up to 5 days per year. Much of the Arctic ice today is younger and thinner than the multiyear ice that was once more widespread in the Arctic Ocean, leaving it more vulnerable to variations in cloud cover, storms, and winds.
Since 2010, changing cloud patterns have reduced the amount of sunlight reaching parts of the Arctic Ocean. The result has been a melt season that fluctuates from one year to the next but remains relatively stable over longer periods. The right map above reflects this shift, with the lighter blues and reds showing the more modest rates of change during that decade.
These findings don’t suggest that shifts in Earth’s climate have stopped affecting the Arctic. The region continues to warm nearly four times faster than the global average, and the remaining sea ice is substantially thinner than it was several decades ago. Instead, the study suggests that the Arctic may have entered a new phase, in which annual weather patterns exert a stronger influence on melt season than they once did.
“Melt season length is much more dependent on atmospheric effects,” Boisvert said. “They seem to be playing a bigger role because the ice is generally thinner and more vulnerable to begin with.”
The researchers caution that the apparent stabilization may prove temporary. Thick Arctic ice still exists throughout the year to the north of Greenland and the Canadian Arctic Archipelago. Continued thinning of ice in those regions could trigger another period of rapid sea ice loss, with the potential to further extend the melt season.
For now, the study highlights the importance of continued satellite observations of Arctic sea ice and the energy balance that controls its growth and melting. Whether the recent stabilization represents a lasting change in the melt season or a pause before another period of rapid change remains an open question.
NASA Earth Observatory images by Michala Garrison, using data from Boisvert, L., et al. (2026). Story by James Riordon/NASA’s Earth Science News Team.
References & Resources
- Boisvert, L., et al. (2026) A recent stabilization in the lengthening of the Arctic sea ice melt season into a highly variable regime. Communications Earth & Environment, 7 (552).
- Markus, T., et al. (2009) Recent changes in Arctic sea ice melt onset, freezeup, and melt season length. JGR Oceans, 114 (C12).
- NASA Earth Observatory (2016, September 16) Sea Ice. Accessed September 17, 2026.
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APOD: 2026 September 20 – Analemma over the Callanish Stones
APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Analemma over the Callanish Stones
Explanation: If you went outside at the same time every day and took a picture that included the Sun, how would the Sun’s position change? A visual answer to that question is an analemma, a composite image taken from the same spot at the same time over the course of a year. The featured analemma was composed from images taken every few days at noon near the village of Callanish in the Outer Hebrides in Scotland, UK. In the foreground are the Callanish Stones, a stone circle built around 2700 BC during humanity’s Bronze Age. It is not known if the placement of the Callanish Stones has or had astronomical significance. The ultimate causes for the figure-8 shape of this and all analemmas are the tilt of the Earth axis and the ellipticity of the Earth’s orbit around the Sun. At the solstices, the Sun will appear at the top or bottom of an analemma. The featured image was taken near the December solstice and so the Sun appears near the bottom. Equinoxes, however, correspond to analemma middle points — not the intersection point. In two days there will be an equinox (“equal night”), when day and night are equal over all of planet Earth. Many cultures celebrate a change of season at an equinox.
APOD’s main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod
Tomorrow’s picture: open space
| Date | September 20, 2026 |
|---|---|
| Credit & Copyright: | Giuseppe Petricca |
| Authors & editors: | Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti, Keighley Rockcliffe |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |
Source: science.nasa.gov
NASA Invites Media to Albania Artemis Accords Signing Ceremony
Credit: NASA
The Republic of Albania will sign the Artemis Accords during a ceremony at 12 p.m. EDT on Monday, Sept. 21, at NASA Headquarters in Washington, becoming the 73rd country signatory.
NASA Deputy Administrator Matt Anderson will host Albania’s Minister for Europe and Foreign Affairs Ferit Hoxha and Ambassador of the Republic of Albania to the United States Ervin Bushati for the ceremony, together with U.S. Department of State officials.
This event is in person only. Media interested in attending must RSVP no later than 10 a.m. on Sept. 21 to: [email protected]. NASA’s media accreditation policy is online.
In 2020, during the first Trump Administration, the United States, led by NASA and the State Department, joined with seven other founding nations to establish the Artemis Accords, responding to the growing interest in lunar activities by both governments and private companies.
The Artemis Accords introduced the first set of practical principles aimed at enhancing the safety, transparency, and coordination of civil space exploration on the Moon, Mars, and beyond.
Learn more about the Artemis Accords at:
https://www.nasa.gov/artemis-accords
-end-
Camille Gallo / Elizabeth Shaw
Headquarters, Washington
202-358-1600
[email protected] / [email protected]
Source: www.nasa.gov
APOD: 2026 September 19 – A Zodiacal Night
APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
A Zodiacal Night
Explanation: Also known as the false dawn, a luminous band of zodiacal light is captured in this dark night skyscape. The serene view was recorded just before the beginning of astronomical twilight during September’s star party at the remote Hanle Dark Sky Reserve, Ladakh, India, planet Earth. At about 4,500 meters altitude, the dark sky reserve presents a haven for hardy stargazing and astrophotography enthusiasts. While meteors streak through the night, bright planet Jupiter appears immersed in the faint zodiacal glow near the eastern horizon. Follow the zodiacal band toward the zenith to find open star cluster M44 and a yellowish tinged planet Mars near the center of the frame. In fact, serendipitous detections of interplanetary dust by NASA’s Juno spacecraft suggest Mars itself is the source of dust that back scatters sunlight and creates zodiacal light in planet Earth’s night.
APOD’s main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod
Tomorrow’s picture: only sunny days
| Date | September 19, 2026 |
|---|---|
| Credit & Copyright: | Neelam and Ajay Talwar (TWAN) |
| Authors & editors: | Jerry Bonnell, Cecilia Chirenti, Robert Nemiroff, Keighley Rockcliffe |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |
Source: science.nasa.gov
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NASA Awards Launch Services for StarBurst Gamma-Ray Detector
Credit: NASA
NASA has selected SpaceX to provide launch services for the agency’s StarBurst mission, a small satellite designed to investigate neutron star mergers and the origins of short gamma-ray bursts.
StarBurst will launch aboard a Bandwagon rideshare mission on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida no earlier than 2028.
The selection is a firm-fixed-price task order under NASA’s VADR (Venture-Class Acquisition of Dedicated and Rideshare) launch services contract. This indefinite-delivery/indefinite-quantity contract allows NASA to acquire launch services during a 10-year ordering period, with a maximum total value of $1 billion across all contracts.
The StarBurst mission is designed to observe the entire portion of the sky not blocked by Earth to search for brief, powerful explosions called gamma-ray bursts. The satellite will focus on detecting the initial high-energy emission from short gamma-ray bursts, which occur when dense stellar remnants called neutron stars merge.
By combining StarBurst’s observations with gravitational-wave measurements and follow-up observations from other telescopes, researchers will study these events through multiple types of signals, an approach known as multimessenger astronomy.
StarBurst is part of NASA’s Astrophysics Pioneers Program, which supports lower-cost investigations using small spacecraft and other platforms.
NASA’s Launch Services Program Office, based at the agency’s Kennedy Space Center in Florida, manages the VADR contract.
For more information about NASA’s StarBurst, visit:
https://science.nasa.gov/mission/starburst
-end-
Joshua Finch / Jimi Russell
Headquarters, Washington
202-358-1100
[email protected] / [email protected]
Leejay Lockhart
Kennedy Space Center, Fla.
321-747-8310
[email protected]
Source: www.nasa.gov
APOD: 2026 September 18 – Messier 33: The Triangulum Galaxy
APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Messier 33: The Triangulum Galaxy
Explanation: The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, Messier 33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and astronomers in these two galaxies would likely have spectacular views of each other’s grand spiral star systems. As for the view from the Milky Way, this sharp telescopic image shows off M33’s blue star clusters and pinkish star forming regions along the galaxy’s loosely wound spiral arms. In fact, the cavernous NGC 604 is the brightest star forming region, seen here at about the 5 o’clock position from the galaxy center. Like M31, M33’s population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick for establishing the distance scale of the Universe.
APOD’s main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod
Tomorrow’s picture: star party weekend
| Date | September 18, 2026 |
|---|---|
| Credit & Copyright: | George Chatzifrantzis |
| Authors & editors: | Jerry Bonnell, Cecilia Chirenti, Robert Nemiroff, Keighley Rockcliffe |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |
Source: science.nasa.gov