Image of the day

Captured by
Terry Wood

Jupiter (clearer) Nov 5th 2023 w/Mewlon 180c

My Account

New to Astromart?

Register an account...

Need Help?

News

So, How Much Does Our Milky Way Galaxy Weigh?

Posted by Guy Pirro 03/09/2019 11:53AM

So, How Much Does Our Milky Way Galaxy Weigh?

We can't put the whole Milky Way Galaxy on a scale, but astronomers have been able to come up with one of the most accurate measurements yet of our galaxy's mass. Curious astronomers teamed up the Hubble Space Telescope and European Space Agency's Gaia satellite to precisely study the motions of globular star clusters that orbit our galaxy like bees around a hive. The faster the clusters move under the entire galaxy's gravitational pull, the more massive it is. The researchers concluded the galaxy weighs 1.5 trillion solar masses (one solar mass is the mass of our Sun). However most of it locked up in dark matter. The new mass estimate puts our galaxy on the beefier side, compared to other galaxies in the universe. The lightest galaxies are around a billion solar masses, while the heaviest are 30 trillion, or 30,000 times more massive.

Kiss the Sky Tonight -- Month of March 2019

Posted by Guy Pirro 03/02/2019 12:33AM

Kiss the Sky Tonight -- Month of March 2019

Welcome to the night sky report for March 2019 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. In March, the stars of spring lie eastward. Look for the constellations Gemini and Cancer to spot interesting celestial features like the Beehive Cluster. The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

Is the Universe Hiding its Missing Mass in the Warm-Hot Intergalactic Medium?

Posted by Guy Pirro 02/23/2019 04:58PM

Is the Universe Hiding its Missing Mass in the Warm-Hot Intergalactic Medium?

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the “normal” matter in the Universe. New results from NASA’s Chandra X-ray Observatory may have helped them locate this elusive expanse of missing matter. In the time between the first few minutes and the first billion years or so, much of the normal matter (meaning hydrogen, helium and other elements) made its way into cosmic dust, gas, and objects such as stars and planets that telescopes can see in the present day Universe. The problem is that when astronomers add up the mass of all the normal matter in the present day Universe, about a third of it can't be found. One idea is that the missing mass gathered into gigantic strands or filaments of “Warm” (temperature less than 100,000 Kelvin) and “Hot” (temperature greater than 100,000 Kelvin) gas in intergalactic space. These filaments are known by astronomers as the "Warm-Hot Intergalactic Medium" or WHIM. They are invisible to optical light telescopes, but some of the warm gas in filaments has been detected in ultraviolet light. Using a new technique, researchers have found new and strong evidence for the hot component of the WHIM based on data from Chandra and other telescopes. (Please note that the missing mass described here is distinct from the still mysterious dark matter).

Earth’s Magnetic Field Vibrates Like a Drum

Posted by Guy Pirro 02/17/2019 04:35PM

Earth’s Magnetic Field Vibrates Like a Drum

Using data from NASA’s THEMIS mission, scientists have discovered ¬that when the Earth’s magnetopause is struck by a jet of plasma from the Sun, it vibrates like a drum, with waves echoing back and forth along its surface, much like they do on top of a drumhead. The new discovery comes several decades after such behavior was first theorized.

Hey… We’re Over Here – Powerful Laser Could be Used as a Beacon to Attract Alien Attention to Earth

Posted by Guy Pirro 02/08/2019 06:48PM

Hey… We’re Over Here – Powerful Laser Could be Used as a Beacon to Attract Alien Attention to Earth

If extraterrestrial intelligence exists somewhere in our galaxy, a new MIT study proposes that laser technology on Earth could, in principle, be fashioned into something of a planetary porch light -- a beacon strong enough to attract attention from as far away as 20,000 light years. The findings suggest that if a high-powered 1 to 2 megawatt laser were focused through a massive 30 to 45 meter telescope and aimed out into space, the combination would produce a beam of infrared radiation strong enough to stand out from the sun’s energy. Such a signal could be detectable by alien astronomers performing a cursory survey of our section of the Milky Way -- especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light years away that hosts seven exo-planets, three of which are potentially habitable.

Kiss the Sky Tonight -- Month of February 2019

Posted by Guy Pirro 01/29/2019 10:18AM

Kiss the Sky Tonight -- Month of February 2019

Welcome to the night sky report for February 2019 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. In February, the Winter Triangle is your guide to the night sky. The northern hemisphere is treated to views of the stars Procyon, Sirius, and Betelgeuse. Keep watching for the awe-inspiring views of the Orion Nebula, which is sculpted by the stellar winds of central bright stars. The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

Mystery Orbits in Outermost Reaches of Solar System not Caused by ‘Planet Nine’

Posted by Guy Pirro 01/21/2019 09:27AM

Mystery Orbits in Outermost Reaches of Solar System not Caused by ‘Planet Nine’

The strange orbits of some objects in the farthest reaches of our solar system, hypothesized by some astronomers to be perturbed by an unknown planet (Planet 9), can instead be explained by the combined gravitational force of small objects in the Kuiper Belt orbiting the Sun beyond Neptune. While the new theory is not the first to propose that the gravitational forces of a massive disc made of small objects could avoid the need for a ninth planet, it is the first such theory which is able to explain the significant features of the observed orbits while accounting for the mass and gravity of the other eight planets in our solar system.

White Dwarfs Have Solid Crystalline Cores Made of Oxygen and Carbon

Posted by Guy Pirro 01/15/2019 06:03PM

White Dwarfs Have Solid Crystalline Cores Made of Oxygen and Carbon

White dwarf stars are some of the oldest stellar objects in the universe. They are incredibly useful to astronomers, as their predictable lifecycle allows them to be used as cosmic clocks to estimate the age of groups of neighboring stars to a high degree of accuracy. White dwarfs are the remaining cores of red giants after these huge stars have died and shed their outer layers. As they cool, they release their stored up heat over the course of billions of years. Now, the first direct evidence of white dwarf stars cooling and solidifying into crystals has been discovered by astronomers at the University of Warwick in the UK… And it turns out that our skies are filled with them – White dwarfs made of solid oxygen and carbon formed through a phase transition process similar to when water turns into ice, but at much higher temperatures and pressures.

Kiss the Sky Tonight -- Month of January 2019

Posted by Guy Pirro 01/08/2019 08:48PM

Kiss the Sky Tonight -- Month of January 2019

Happy New Year and welcome to the night sky report for January 2019 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. In January, the northern hemisphere features beautiful views of the binary star Capella - a pair of giant yellow stars, Aldebaran - a red giant star, two star clusters—the Hyades (Caldwell 41) and the Pleiades (M45), and the Crab Nebula (M1). The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

The Falcon (New Horizons) and the Snowman (Ultima Thule)

Posted by Guy Pirro 01/04/2019 02:48AM

The Falcon (New Horizons) and the Snowman (Ultima Thule)

Following its successful fly-by of Pluto in July 2015, NASA's New Horizons mission has now performed a second fly-by – this time of an entirely new kind of world deep in the Kuiper Belt. NASA scientists released the first detailed images of the most distant object ever explored — the Kuiper Belt object Ultima Thule. Its remarkable appearance -- two spherical objects touching together in the shape of a snowman, unlike anything we've seen before -- sheds new light on the processes that built our Solar System planets four and a half billion years ago. New Horizon’s images of Ultima Thule unveil the very first stages of our Solar System's history.

2019 and Beyond...

Posted by Paul Walsh 01/01/2019 05:59PM

Wherever you are....

Posted by Paul Walsh 12/21/2018 09:06AM

Tangled Magnetic Fields in Black Holes Create the Most Powerful Particle Accelerators in the Universe

Posted by Guy Pirro 12/15/2018 02:53AM

Tangled Magnetic Fields in Black Holes Create the Most Powerful Particle Accelerators in the Universe

Magnetic field lines tangled like spaghetti in a bowl, as found in black holes, might be behind the most powerful particle accelerators in the universe. That’s the result of a new computational study by researchers from the Department of Energy’s SLAC National Accelerator Laboratory, which simulated particle emissions from distant active galaxies. SLAC scientists have found a new way to explain how these black hole plasma jets boost particles to the highest energies observed in the universe. The results could prove useful for fusion and accelerator research on Earth.

Kiss the Sky Tonight -- Month of December 2018

Posted by Guy Pirro 12/03/2018 08:30AM

Kiss the Sky Tonight -- Month of December 2018

Welcome to the night sky report for December 2018 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. Saturn’s iconic rings are clearly visible with backyard telescopes in early December. Mercury and Venus appear later in the month. Also look for Eta Cassiopeiae, a double star, with binoculars or a small telescope to discern its gold and blue hues. Finally, don’t miss the mid-December Geminid meteor shower. You could see as many as 60 colorful meteors per hour. The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

We Give Thanks

11/22/2018 05:05AM