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Hubble Observations Support Black Hole Explanation For Active Galaxies
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Healing continues in the atmosphere over the Antarctic: a hole that opens annually in the ozone layer over Earth’s southern pole was relatively small in 2024 compared to other years. Scientists with NASA and the National Oceanic and Atmospheric Administration (NOAA) project the ozone layer could fully recover by 2066.
This map shows the size and shape of the ozone hole over the South Pole on Sept. 28, 2024, the day of its annual maximum extent, as calculated by the NASA Ozone Watch team. Scientists describe the ozone “hole” as the area in which ozone concentrations drop below the historical threshold of 220 Dobson units. During the peak of ozone depletion season from Sept. 7 through Oct. 13, the 2024 area of the ozone hole ranked the seventh smallest since recovery began in 1992, when the Montreal Protocol, a landmark international agreement to phase out ozone-depleting chemicals, began to take effect.
At almost 8 million square miles (20 million square kilometers), the monthly average ozone-depleted region in the Antarctic this year was nearly three times the size of the contiguous U.S. The hole reached its greatest one-day extent for the year on Sept. 28 at 8.5 million square miles (22.4 million square kilometers).
The improvement is due to a combination of continuing declines in harmful chlorofluorocarbon (CFC) chemicals, along with an unexpected infusion of ozone carried by air currents from north of the Antarctic, scientists said.
The ozone hole over Antarctica reached its annual maximum extent on Sept. 28, 2024, with an area of 8.5 million square miles (22.4 million square kilometers).
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta In previous years, NASA and NOAA have reported the ozone hole ranking using a time frame dating back to 1979, when scientists began tracking Antarctic ozone levels with satellite data. Using that longer record, this year’s hole ranked 20th smallest in area across the 45 years of observations.
“The 2024 Antarctic hole is smaller than ozone holes seen in the early 2000s,” said Paul Newman, leader of NASA’s ozone research team and chief scientist for Earth sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The gradual improvement we’ve seen in the past two decades shows that international efforts that curbed ozone-destroying chemicals are working.”
The ozone-rich layer high in the atmosphere acts as a planetary sunscreen that helps shield us from harmful ultraviolet (UV) radiation from the Sun. Areas with depleted ozone allow more UV radiation, resulting in increased cases of skin cancer and cataracts. Excessive exposure to UV light can also reduce agricultural yields as well as damage aquatic plants and animals in vital ecosystems.
Scientists were alarmed in the 1970s at the prospect that CFCs could eat away at atmospheric ozone. By the mid-1980s, the ozone layer had been depleted so much that a broad swath of the Antarctic stratosphere was essentially devoid of ozone by early October each year. Sources of damaging CFCs included coolants in refrigerators and air conditioners, as well as aerosols in hairspray, antiperspirant, and spray paint. Harmful chemicals were also released in the manufacture of insulating foams and as components of industrial fire suppression systems.
The Montreal Protocol was signed in 1987 to phase out CFC-based products and processes. Countries worldwide agreed to replace the chemicals with more environmentally friendly alternatives by 2010. The release of CFC compounds has dramatically decreased following the Montreal Protocol. But CFCs already in the air will take many decades to break down. As existing CFC levels gradually decline, ozone in the upper atmosphere will rebound globally, and ozone holes will shrink.
Ozone 101 is the first in a series of explainer videos outlining the fundamentals of popular Earth science topics. Let’s back up to the basics and understand what caused the Ozone Hole, its effects on the planet, and what scientists predict will happen in future decades.
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta “For 2024, we can see that the ozone hole’s severity is below average compared to other years in the past three decades, but the ozone layer is still far from being fully healed,” said Stephen Montzka, senior scientist of the NOAA Global Monitoring Laboratory.
Researchers rely on a combination of systems to monitor the ozone layer. They include instruments on NASA’s Aura satellite, the NOAA-20 and NOAA-21 satellites, and the Suomi National Polar-orbiting Partnership satellite, jointly operated by NASA and NOAA.
NOAA scientists also release instrumented weather balloons from the South Pole Baseline Atmospheric Observatory to observe ozone concentrations directly overhead in a measurement called Dobson Units. The 2024 concentration reached its lowest value of 109 Dobson Units on October 5. The lowest value ever recorded over the South Pole was 92 Dobson Units in October 2006.
NASA and NOAA satellite observations of ozone concentrations cover the entire ozone hole, which can produce a slightly smaller value for the lowest Dobson Unit measurement.
“That is well below the 225 Dobson Units that was typical of the ozone cover above the Antarctic in 1979,” said NOAA research chemist Bryan Johnson. “So, there’s still a long way to go before atmospheric ozone is back to the levels before the advent of widespread CFC pollution.”
View the latest status of the ozone layer over the Antarctic with NASA’s ozone watch.
By James Riordon
NASA’s Earth Science News Team
Media Contact:
Jacob Richmond
NASA’s Goddard Space Flight Center, Greenbelt, Md.
jacob.richmond@nasa.gov
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Last Updated Oct 30, 2024 LocationGoddard Space Flight Center Related Terms
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By NASA
ESA/Hubble & NASA, M. Sun The spiral galaxy in this NASA/ESA Hubble Space Telescope image is IC 3225. It looks remarkably as if it was launched from a cannon, speeding through space like a comet with a tail of gas streaming from its disk behind it. The scenes that galaxies appear in from Earth’s point of view are fascinating; many seem to hang calmly in the emptiness of space as if hung from a string, while others star in much more dynamic situations!
Appearances can be deceiving with objects so far from Earth — IC 3225 itself is about 100 million light-years away — but the galaxy’s location suggests some causes for this active scene, because IC 3225 is one of over 1,300 members of the Virgo galaxy cluster. The density of galaxies in the Virgo cluster creates a rich field of hot gas between them, called ‘intracluster medium’, while the cluster’s extreme mass has its galaxies careening around its center in some very fast orbits. Ramming through the thick intracluster medium, especially close to the cluster’s center, places enormous ‘ram pressure’ on the moving galaxies that strips gas out of them as they go.
As a galaxy moves through space, the gas and dust that make up the intracluster medium create resistance to the galaxy’s movement, exerting pressure on the galaxy. This pressure, called ram pressure, can strip a galaxy of its star-forming gas and dust, reducing or even stopping the creation of new stars. Conversely, ram pressure can also cause other parts of the galaxy to compress, which can boost star formation. IC 3225 is not so close to the cluster core right now, but astronomers have deduced that it has undergone ram pressure stripping in the past. The galaxy looks compressed on one side, with noticeably more star formation on that leading edge (bottom-left), while the opposite end is stretched out of shape (upper-right). Being in such a crowded field, a close call with another galaxy may also have tugged on IC 3225 and created this shape. The sight of this distorted galaxy is a reminder of the incredible forces at work on astronomical scales, which can move and reshape entire galaxies!
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By NASA
Hubble Space Telescope Home Hubble Sees a Celestial… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 2 min read
Hubble Sees a Celestial Cannonball
This NASA/ESA Hubble Space Telescope image features the spiral galaxy IC 3225. ESA/Hubble & NASA, M. Sun The spiral galaxy in this NASA/ESA Hubble Space Telescope image is IC 3225. It looks remarkably as if it was launched from a cannon, speeding through space like a comet with a tail of gas streaming from its disk behind it. The scenes that galaxies appear in from Earth’s point of view are fascinating; many seem to hang calmly in the emptiness of space as if hung from a string, while others star in much more dynamic situations!
Appearances can be deceiving with objects so far from Earth — IC 3225 itself is about 100 million light-years away — but the galaxy’s location suggests some causes for this active scene, because IC 3225 is one of over 1,300 members of the Virgo galaxy cluster. The density of galaxies in the Virgo cluster creates a rich field of hot gas between them, called ‘intracluster medium’, while the cluster’s extreme mass has its galaxies careening around its center in some very fast orbits. Ramming through the thick intracluster medium, especially close to the cluster’s center, places enormous ‘ram pressure’ on the moving galaxies that strips gas out of them as they go.
As a galaxy moves through space, the gas and dust that make up the intracluster medium create resistance to the galaxy’s movement, exerting pressure on the galaxy. This pressure, called ram pressure, can strip a galaxy of its star-forming gas and dust, reducing or even stopping the creation of new stars. Conversely, ram pressure can also cause other parts of the galaxy to compress, which can boost star formation. IC 3225 is not so close to the cluster core right now, but astronomers have deduced that it has undergone ram pressure stripping in the past. The galaxy looks compressed on one side, with noticeably more star formation on that leading edge (bottom-left), while the opposite end is stretched out of shape (upper-right). Being in such a crowded field, a close call with another galaxy may also have tugged on IC 3225 and created this shape. The sight of this distorted galaxy is a reminder of the incredible forces at work on astronomical scales, which can move and reshape entire galaxies!
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Oct 24, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Hubble Space Telescope The Universe Keep Exploring Discover More Topics From NASA
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
This September 2024 aerial photograph shows the coastal launch range at NASA’s Wallops Flight Facility on Virginia’s Eastern Shore. Wallops is the agency’s only owned-and-operated launch range.Courtesy Patrick J. Hendrickson; used with permission NASA’s Wallops Flight Facility in Virginia is scheduled to support the launch of a suborbital sounding rocket for the U.S. Department of Defense during a launch window that runs 5 p.m. to 11 p.m. EDT each day from Wednesday, Oct. 23 to Friday, Oct. 25.
No real-time launch status updates will be available. The launch will not be livestreamed nor will launch status updates be provided during the countdown. The Wallops Visitor Center will be closed to the public.
The rocket launch is expected to be visible from the Chesapeake Bay region.
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Last Updated Oct 22, 2024 LocationWallops Flight Facility Related Terms
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By NASA
Hubble Space Telescope Home Hubble Captures a New View of… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 2 min read
Hubble Captures a New View of Galaxy M90
This eye-catching image offers us a new view of the spiral galaxy Messier 90 from the NASA/ESA Hubble Space Telescope. ESA/Hubble & NASA, D. Thilker, J This NASA/ESA Hubble Space Telescope image features the striking spiral galaxy Messier 90 (M90, also NGC 4569), located in the constellation Virgo. In 2019, Hubble released an image of M90 created with Wide Field and Planetary Camera 2 (WFPC2) data taken in 1994, soon after its installation. That WFPC2 image has a distinctive stair-step pattern due to the layout of its sensors. Wide Field Camera 3 (WFC3) replaced WFPC2 in 2009 and Hubble used WFC3 when it turned its aperture to Messier 90 again in 2019 and 2023. That data resulted in this stunning new image, providing a much fuller view of the galaxy’s dusty disk, its gaseous halo, and its bright core.
The inner regions of M90’s disk are sites of star formation, seen here in red H-alpha light from nebulae. M90 sits among the galaxies of the relatively nearby Virgo Cluster, and its orbit took M90 on a path near the cluster’s center about three hundred million years ago. The density of gas in the inner cluster weighed on M90 like a strong headwind, stripping enormous quantities of gas from the galaxy and creating the diffuse halo we see around it. This gas is no longer available to form new stars in M90, with the spiral galaxy eventually fading as a result.
M90 is located 55 million light-years from Earth, but it’s one of the very few galaxies getting closer to us. Its orbit through the Virgo cluster has accelerated so much that M90 is in the process of escaping the cluster entirely. By happenstance, it’s moving in our direction. Astronomers have measured other galaxies in the Virgo cluster at similar speeds, but in the opposite direction. As M90 continues to move toward us over billions of years, it will also be evolving into a lenticular galaxy.
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Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Oct 17, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Hubble Space Telescope Science Mission Directorate Spiral Galaxies The Universe Keep Exploring Discover More Topics From NASA
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