Astronomy Picture of the Day from NASA
Image taken by Alexandros Maragos
There was a supermoon yesterday (August 19th), which means that the moon appears larger and brighter than usual! Alexandros Maragos took this image as the blue supermoon was approaching its peak at the Temple of Poseidon in Greece. What an incredible image!
Every February 2, we wonder if Punxsutawney Phil will see his shadow.
In Saturn’s case, astronomers know some of Saturn’s moons will cast shadows across the planet’s iconic rings every 15 years. This effect only occurs when the planet’s rings are perpendicular to the Sun. The next time this will happen is in May 2025.
Watch as four of Saturn’s moons orbit the planet, based on images taken by the Hubble Space Telescope over a 9.5-hour span in 1995. Enceladus is first and Mimas is close behind. Both of these moons cast small shadows on Saturn, but among the two, only Enceladus’ shadow cuts across the rings. Dione follows next and casts a long shadow across the planet’s rings. About 12 seconds in, the moon Tethys moves swiftly behind the planet toward the right.
Credit: NASA/ESA/STScI.
Handy direct image addresses:
Wow - was also an APOD!
Did a reverse image search on the 2nd one to find the original original source. I found some book covers, but eventually this esahubble.org press release revealed itself as at least an official source of the original image from Nov. 2005! It's NGC 346 (the star cluster) and a gorgeous backdrop of gas in the Small Magellanic Cloud.
Sources for banner and profile picture
We'll be open tonight, Wed. 4/23, 8:30 - 9:45 pm! We expect lovely skies.
Happy Wednesday! It's time for an astronomy word of the day!
Asterism - an asterism is any prominent star pattern that isn’t a whole constellation, such as the Northern Cross or the Big Dipper (pictured below)
Definition from: https://skyandtelescope.org/astronomy-terms/ Image from: https://skyandtelescope.org/astronomy-news/a-new-way-to-see-the-big-dipper/
In short: reblogging is awesome. Reposting isn't.
The brown dwarf W1935 is a bit of a mystery. Astronomers using the James Webb Space Telescope picked up glowing methane—a sign that the object’s upper atmosphere is being heated. But the brown dwarf has no host star, so where could the heat be coming from?
In our solar system, Jupiter and Saturn show methane emission due to the presence of auroras—what we call the Northern Lights on Earth. W1935 might also have auroras, which could be powered by energetic particles from a nearby, active moon, like Jupiter’s Io: https://webbtelescope.pub/4aKMkBF
The Cone Nebula from Hubble Image Credit: Hubble Legacy Archive, NASA, ESA - Processing & Licence: Judy Schmidt
Explanation: Stars are forming in the gigantic dust pillar called the Cone Nebula. Cones, pillars, and majestic flowing shapes abound in stellar nurseries where natal clouds of gas and dust are buffeted by energetic winds from newborn stars. The Cone Nebula, a well-known example, lies within the bright galactic star-forming region NGC 2264. The Cone was captured in unprecedented detail in this close-up composite of several observations from the Earth-orbiting Hubble Space Telescope. While the Cone Nebula, about 2,500 light-years away in Monoceros, is around 7 light-years long, the region pictured here surrounding the cone’s blunted head is a mere 2.5 light-years across. In our neck of the galaxy that distance is just over half way from our Sun to its nearest stellar neighbors in the Alpha Centauri star system. The massive star NGC 2264 IRS, seen by Hubble’s infrared camera in 1997, is the likely source of the wind sculpting the Cone Nebula and lies off the top of the image. The Cone Nebula’s reddish veil is produced by dust and glowing hydrogen gas.
∞ Source: apod.nasa.gov/apod/ap240204.html
Happy fun fact Friday!
Did you know that the largest canyon system in the solar system is Valles Marineris on Mars? The image shows the Valles Marineris compared to the US coast to coast and the Grand Canyon!
Source: NASA
Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy’s disturbing the primary galaxy’s spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger.
A giant galaxy interacting with its satellites is common. A satellite’s gravity could attract one of the primary’s spiral arms, or the secondary satellite’s path could coincide with the position of the primary satellite’s and so would dive into the primary galaxy (the Sagittarius Dwarf Elliptical Galaxy into the Milky Way being an example of the latter). That can possibly trigger a small amount of star formation. Such orphaned clusters of stars were sometimes referred to as “blue blobs” before they were recognized as stars.
Colliding galaxies are common during galaxy evolution. The extremely tenuous distribution of matter in galaxies means these are not collisions in the traditional sense of the word, but rather gravitational interactions.
Colliding may lead to merging if two galaxies collide and do not have enough momentum to continue traveling after the collision. In that case, they fall back into each other and eventually merge into one galaxy after many passes through each other. If one of the colliding galaxies is much larger than the other, it will remain largely intact after the merger. The larger galaxy will look much the same, while the smaller galaxy will be stripped apart and become part of the larger galaxy. When galaxies pass through each other, unlike during mergers, they largely retain their material and shape after the pass.
Galactic collisions are now frequently simulated on computers, which use realistic physics principles, including the simulation of gravitational forces, gas dissipation phenomena, star formation, and feedback. Dynamical friction slows the relative motion galaxy pairs, which may possibly merge at some point, according to the initial relative energy of the orbits.
Astronomers have estimated the Milky Way galaxy, will collide with the Andromeda galaxy in about 4.5 billion years. It is thought that the two spiral galaxies will eventually merge to become an elliptical galaxy or perhaps a large disk galaxy.
Source
Image credit: NASA/ESA & Hubble (procesed by: Steve Byrne & Judy Schmidt)
Animation
We'll be open tonight, Wed. 4/30, 8:30 - 9:45 pm!
STEM Education, Astrophysics Research, Astrophotography, and Outreach located at 24 Park Ave., Bridgewater MA. You'll find us on the two outdoor balconies on the 5th floor, and you'll find our official website here: https://www.bridgew.edu/center/case/observatory .
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