TYB
NASA Astronomy Picture of the Day
Feb 18, 2024
Hoag's Object: A Nearly Perfect Ring Galaxy
Is this one galaxy or two? This question came to light in 1950 when astronomer Arthur Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark. How Hoag's Object formed, including its nearly perfectly round ring of stars and gas, remains unknown. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished. The featured photo was taken by the Hubble Space Telescope and reprocessed using an artificially intelligent de-noising algorithm. Observations in radio waves indicate that Hoag's Object has not accreted a smaller galaxy in the past billion years. Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Many galaxies far in the distance are visible toward the right, while coincidentally, visible in the gap at about seven o'clock, is another but more distant ring galaxy.
https://apod.nasa.gov/apod/astropix.html?
2024 Is a Leap Year! When Are Leap Years and Why Do We Have Them?
February 1, 2024
Simply put, a leap year is a year with an extra day—February 29—added nearly every four years to the calendar year.
Why Are Leap Years Necessary?
Adding an extra day every four years keeps our calendar aligned correctly with the astronomical seasons, since a year according to the Gregorian calendar (365 days) and a year according to Earth’s orbit around the Sun (approximately 365.25 days) are not the same length of time. Without this extra day, our calendar and the seasons would gradually get out of sync. (Keep reading for a longer explanation.)
Because of this extra day, a leap year has 366 days instead of 365. Additionally, a leap year does not end and begins on the same day of the week as a non–leap year does.
How Do You Know If It’s a Leap Year?
Generally, a leap year happens every four years, which, thankfully, is a relatively simple pattern to remember. However, there is a little more to it than that.
Here are the rules of leap years:
A year may be a leap year if it is evenly divisible by 4.
Years divisible by 100 (century years such as 1900 or 2000) cannot be leap years unless they are also divisible by 400. (For this reason, the years 1700, 1800, and 1900 were not leap years, but the years 1600 and 2000 were.)
If a year satisfies both the rules above, it is a leap year.
Why Do We Need Leap Years?
The short explanation for why we need leap years is that our calendar needs to stay aligned with the astronomical seasons.
One orbit of Earth around the Sun takes approximately 365.25 days—a little more than our Gregorian calendar’s nice, round number of 365. Because the calendar does not account for the extra quarter of a day that the Earth requires to complete its orbit around the Sun, it doesn’t completely align with the solar year.
Because of this .25 difference, our calendar gradually gets out of sync with the seasons. Adding an extra day, aka a “leap day,” to the calendar every four years brings the calendar in line and, therefore, realigns it with the seasons.
Without leap days, the calendar would be off by 5 hours, 48 minutes, and 45 seconds more each year.
After 100 years, the seasons would be off by 25 days! Eventually, the months we call February and March would feel like summer in the Northern Hemisphere.
The extra leap day adjusts this drift, but it’s not a perfect match: Adding a leap day every four years overcompensates by a few extra seconds each leap year, adding up to about three extra days every 10,000 years.
Leap Year Facts and Folklore
Ages ago, Leap Day was known as “Ladies Day” or “Ladies’ Privilege,” as it was the one day when women were free to propose to men. Today, Sadie Hawkins Day sometimes applies to Feb 29 (leap day), based on this older tradition.
According to folklore, the weather always changes on Friday in a leap year.
“Leap year was ne’er a good sheep year” (old proverb)
Are Leap Years Bad Luck?
Many feel that to be born on Leap Day, thereby becoming a “leapling,” is a sign of good luck.
In some cultures, getting married during a leap year is considered bad luck.
We don’t know of any evidence supporting that marriage theory, but we do know that during leap years:
Rome burned (64),
and the Titanic sank (1912).
Also, in leap years:
The Pilgrims landed at Plymouth, Massachusetts (1620),
Benjamin Franklin proved that lightning is electricity (1752),
and gold was discovered in California (1848).
https://www.almanac.com/when-next-leap-year
Korea, NASA to kick off joint air quality research across Asia
Updated : 2024-02-18 16:33
Korea and the United States will kick off a research campaign to uncover the cause of air pollution across Asia during the winter season as part of efforts to better address air quality challenges and come up with policies designed to improve air quality.
The ASIA-AQ, a joint effort by Korea's National Institute of Environmental Research (NIER) and the National Aeronautics and Space Administration (NASA), aims to collect detailed air quality data over several locations in Asia using aircraft, satellites, and ground sites.
It has already completed four flights in the Philippines and Taiwan over the past few weeks.
"This campaign seeks to find the causes behind air quality deteriorating in the Korean Peninsula during wintertime," said Yoo Myung-soo, the NIER director general of the climate and air quality research department, during a media briefing at the Osan Air Base in Pyeongtaek, 60 kilometers south of Seoul, on Friday.
"The results of the joint investigation will also be used to enhance the effectiveness and reliability of domestic policies concerning the atmospheric environment," he added.
The joint research, tentatively set for Feb. 19-26, comes eight years after Korea led the KORUS-AQ campaign with NASA in 2016, which found that 52 percent of ultrafine particles examined in Seoul were picked up from within Korea and 48 percent from overseas, including 34 percent coming in from China.
The main differences between the KORUS-AQ and the new initiative is the time of the year the research is conducted, which changed from spring to winter, and the mobilization of the newly launched GEMS satellite, Barry Lefer of NASA said.
In 2020, Korea launched the world's first geostationary environment satellite, or GEMS, to monitor air pollutants across Asia from 36,000 kilometers above ground.
The research team will also utilize detailed ground measurements from 11 air quality research sites, including in Seoul and on the islands of Baengnyeong and Jeju, and collect aircraft sampling of the lower atmosphere using NASA's DC-8, an in-situ aircraft flying within the altitude of 2,000 feet.
"This means that from the ground we can measure what you breathe but from space we can measure the accumulation of total pollutants," said Jim Crawford from NASA leading the ASIA-AQ project.
The campaign is also designed to cross-check the measurements of the GEMS, which monitors the air quality in Asia eight times a day, as the data requires verification through comparison with ground-based observations.
"It will take time to calibrate the raw data and turn it into data that is useful for science," said Crawford, adding the interpretation and findings from the data will be open to the public the following year. (Yonhap)
https://www.koreatimes.co.kr/www/nation/2024/02/113_368987.html
Private Odysseus moon lander beams home 1st photos from space
Feb 17, 2024
A pioneering moon lander has beamed home its first photos from the final frontier.
Intuitive Machines' robotic Odysseus spacecraft snapped a few selfies with Earth in the background shortly after its Feb. 15 launch atop a SpaceX Falcon 9 rocket — and we can all check them out.
"Intuitive Machines successfully transmitted its first IM-1 mission images to Earth on February 16, 2024. The images were captured shortly after separation from @SpaceX's second stage on Intuitive Machines' first journey to the moon under @NASA's CLPS initiative," the Houston-based company wrote Saturday (Feb. 17) in a post on X that shared four of the photos.
CLPS is the Commercial Lunar Payload Services program, which puts agency science instruments on private robotic moon landers like Odysseus. These instruments are designed to collect data that will aid NASA's Artemis program, which aims to establish a crewed base near the lunar south pole by the end of the 2020s.
Odysseus is carrying six NASA experiments and technology demonstrations, along with six private payloads, on its current IM-1 mission.
IM-1 wasn't the first CLPS effort to get off the ground. That distinction goes to the debut flight of Peregrine, a moon lander built by Pittsburgh company Astrobotic, which launched last month atop a United Launch Alliance Vulcan Centaur rocket.
That launch went well, but Peregrine suffered a fuel leak shortly after separating from the rocket's upper stage. The lander couldn't reach the moon, so its handlers steered it to a controlled destruction in Earth's atmosphere on Jan. 18.
Things have been going better for Odysseus. The lander is healthy and communicating with mission control as it heads toward the moon for a planned Feb. 22 touchdown attempt, Intuitive Machines has said.
Odysseus' various systems are performing normally, including its engine, which just aced a crucial checkout in deep space.
"Intuitive Machines flight controllers successfully fired the first liquid methane and liquid oxygen engine in space, completing the IM-1 mission engine commissioning. This engine firing included a full thrust mainstage engine burn and throttle down-profile necessary to land on the moon," the company said in an X post on Friday evening (Feb. 16).
Success on the upcoming landing try would be historic; no private spacecraft has ever touched down softly on the moon.
Odysseus' liquid methane-liquid oxygen combination, by the way, is also employed by SpaceX's Raptor engines, which power the company's giant new Starship rocket. Starship, which SpaceX is developing to get people to the moon and Mars, is being prepped for its third test flight, which could take place in the coming weeks.
https://www.space.com/intuitive-machines-odysseus-moon-lander-first-photos
NASA Urges U.S. Public To See April 8’s Total Solar Eclipse—And Drops A Home Truth
Feb 17, 2024,07:15pm EST
“If you haven’t seen a total solar eclipse, you haven’t seen anything.” So ends NASA’s new trailer for what is arguably the celestial highlight not only of 2024 but of the entire decade—and possibly many Americans’ lifetimes.
NASA is correct—it’s the sight of your life, and it’s not going to return to North America until 2033 (in Alaska) and 2044 (in Montana and the Dakotas).
Publicizing its plans to broadcast April’s total solar eclipse from locations across the U.S., the space agency’s short trailer on YouTube is high on drama.
Shadow Of The Moon
On Monday, April 8, a path of totality—the moon’s shadow—will travel from Mexico’s Pacific coast to Newfoundland in Canada via parts of 15 U.S. states.
While only those inside a 115-mile wide path will see the eclipse and experience totality—darkness in the day and falling temperatures, everyone else in North America will see a partial solar eclipse of varying degrees.
A Connection To Space
Lasting 1 minute 8 seconds, the video—published on NASA’s YouTube channel—puts the experience of totality front and center. “When you experience an eclipse, you feel a connection to space,” proclaims one voice. “The universe is out there, and it’s affecting us—we are in space,” adds another.
Both quotes relate to the sudden feeling of syzygy—the alignment of the sun, the moon, and you—reported by eclipse chasers as the moon’s shadow sweeps across, suddenly revealing see the sun’s corona to the naked eye.
However, NASA also put out a safety reminder, telling observers that except during the brief total phase of a total solar eclipse, when the moon completely blocks the sun’s bright face, it is not safe to look directly at the sun without specialized eye protection for solar viewing.
When NASA Will Broadcast The Total Solar Eclipse
The video also invites the viewer to “Experience it live with NASA as we travel across the path of a total solar eclipse,” which should be easy to do on April 8 (and may, if skies are cloudy, be the only way to follow the progress of the moon across the sun).
NASA confirmed that it will provide live broadcast coverage on April 8 from 1:00 p.m. to 4:00 p.m. EDT (1700 to 2000 UTC) on NASA TV, NASA.gov, the NASA app, and on YouTube.
Where NASA Will Broadcast The Total Solar Eclipse
NASA will broadcast live to the world from four venues on April 8:
Kerrville Eclipse Festival in Kerrville, Texas (NASA TV)
Indianapolis Motor Speedway, Indiana (NASA TV)
Southern Illinois Crossroads Eclipse Festival in Carbondale, Illinois (NASA Edge)
Great Lakes Science Center’s Total Eclipse Fest 2024 in Cleveland, Ohio (NASA TV)
The total solar eclipse is also set to be streamed live on its YouTube channel by The Discovery Channel from the 2024 Eclipse Over Texas public event in Waco, Texas. It will also be streamed from mobile observatories throughout the path of totality to YouTube by Timeanddate, Slooh and Exploratorium.
https://www.forbes.com/sites/jamiecartereurope/2024/02/17/nasa-urges-us-public-to-see-april-8s-total-solar-eclipse-and-drops-a-home-truth/?sh=1ba6391c1b26