Magazine Posts

NASA Astronomy Picture of the Day:

This tantalizing trio of galaxies sometimes called the Draco Group, is located in the northern constellation of (you guessed it) Draco, the Dragon. From left to right are face-on spiral NGC 5985, elliptical galaxy NGC 5982, and edge-on spiral NGC 5981, all found within this single telescopic field of view that spans a little more than the width of the full moon. While the group is far too small to be a galaxy cluster, and has not been catalogued as a compact galaxy group, the three galaxies all do lie roughly 100 million light-years from planet Earth. Not as well known as other tight groupings of galaxies, the contrast in visual appearance still makes this triplet an attractive subject for astroimagers. On close examination with spectrographs, the bright core of striking spiral NGC 5985 shows prominent emission in specific wavelengths of light, prompting astronomers to classify it as a Seyfert, a type of active galaxy. This impressively deep exposure hints at a faint dim halo along with sharp-edged shells surrounding elliptical NGC 5982, evidence of past galactic mergers. It also reveals many even more distant background galaxies.

Photo by David Vernet , Jean-François Bax , Serge Brunier

NASA Astronomy Picture of the Day:

Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. To investigate Earth-saving strategies, NASA successfully tested the Double Asteroid Redirection Test (DART) mission last year. Of course, rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes create memorable fireball and meteor displays. Today is: Asteroid Day

NASA Astronomy Picture of the Day:

Monitoring 68 pulsars with very large radio telescopes, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has uncovered evidence for the gravitational wave (GW) background by carefully measuring slight shifts in the arrival times of pulses. These shifts are correlated between different pulsars in a way that indicates that they are caused by GWs. This GW background is likely due to hundreds of thousands or even millions of supermassive black hole binaries. Teams in Europe, Asia and Australia have also independently reported their results today. Previously, the LIGO and Virgo detectors have detected higher-frequency GWs from the merging of individual pairs of massive orbiting objects, such as stellar-mass black holes. The featured illustration highlights this spacetime-shaking result by depicting two orbiting supermassive black holes and several of the pulsars that would appear to have slight timing shifts. The imprint these GWs make on spacetime itself is illustrated by a distorted grid. Open Science: Browse 3,000+ codes in the Astrophysics Source Code Library

Photo by Ingo Stiller on Unsplash

NASA Astronomy Picture of the Day:

Unlike most entries in Charles Messier's famous catalog of deep sky objects, M24 is not a bright galaxy, star cluster, or nebula. It's a gap in nearby, obscuring interstellar dust clouds that allows a view of the distant stars in the Sagittarius spiral arm of our Milky Way galaxy. Direct your gaze through this gap with binoculars or small telescope and you are looking through a window over 300 light-years wide at stars some 10,000 light-years or more from Earth. Sometimes called the Small Sagittarius Star Cloud, M24's luminous stars fill this gorgeous starscape. Covering over 3 degrees or the width of 6 full moons in the constellation Sagittarius, the telescopic field of view includes dark markings B92 and B93 near center, along with other clouds of dust and glowing nebulae toward the center of the Milky Way.

Photo by Touhid biplob, CC BY-SA 4.0 , via Wikimedia Commons

When love was young,
my mind was new.
All my thoughts of love,
were about you.

Now I'm an elder,
my mind will stay,
as my thoughts of love,
refuse to go away.

Cecilia Payne's work on the nature of variable stars showed that the wide variation in stellar spectra is due mainly to the different ionization states of the atoms and hence different surface temperatures of the stars, not to different amounts of the elements. Concluding that stars were composed primarily of hydrogen and helium. Her groundbreaking work from almost 100 years ago, was initially rejected because it contradicted the scientific wisdom of the time, which held that there were no significant elemental differences between the Sun and Earth. Independent observations eventually proved she was correct. More

NASA Astronomy Picture of the Day:

These two global views of Mars were captured at ultraviolet wavelengths, beyond the spectrum visible to human eyes. Recorded by the MAVEN spacecraft's Imaging Ultraviolet Spectrograph instrument in July 2022 (left) and January 2023, three otherwise invisible ultraviolet bands are mapped into red, green, and blue colors. That color scheme presents the Red Planet's surface features in shades of tan and green. Haze and clouds appear white or blue, while high altitude ozone takes on a dramatic purple hue. On the left, Mars' south polar ice cap is in brilliant white at the bottom but shrinking during the southern hemisphere's summer season. On the right, the northern hemisphere's polar region is seen shrouded in clouds and atmospheric ozone. Known to some as the Mars Atmosphere and Volatile EvolutioN spacecraft, MAVEN has been exploring Mars' tenuous upper atmosphere, ionosphere, and its interactions with the Sun and solar wind since 2014.

              Ophelia

My sister went with the Angels,
Years before I was born,
Her photo, always displayed,
Was a normal part of our home.

The pain from her early departure,
Came out slowly, a bit at a time,
And yet, not fully understood,
By the mind of the child I was.

Her photo, now in my home,
Is displayed just as before,
And I still wonder why and why not,
Not understanding, yet unable to ignore.

All Copyrights are reserved: Calob 2023

"This is the sight that greeted us as we arrived at Jokulsarlon at 11:30pm. Because of the almost polar location of Iceland, sunlight can illuminate the landscape for 22-23 hours a day, with the sun barely crossing the horizon". Matt Palmer on Unsplash