This Animation Portrays The Creation Of The Cat’s Tail In The Southwest Portion Of Beta Pic’s Secondary

ESA's Gaia Mission has been mapping the Milky Way for over 10 years! Check out its greatest discoveries in this short video (~5 minutes).

Interacting galaxy

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

3/19: Our public night is cancelled. The forecast keeps getting worse. We'll try again next week!

Happy Monday!

Today's picture of the day was taken by Matthew Dominick from the ISS! The image shows a giant jet lightning, which is a new discovery (only 23 years!) and associated with thunderstorms. While regular lightning travels between the ground and the clouds, giant jet lightning bursts upwards.

Sharpening Our View of Climate Change with the Plankton, Aerosol, Cloud, ocean Ecosystem Satellite

As our planet warms, Earth’s ocean and atmosphere are changing.

Climate change has a lot of impact on the ocean, from sea level rise to marine heat waves to a loss of biodiversity. Meanwhile, greenhouse gases like carbon dioxide continue to warm our atmosphere.

NASA’s upcoming satellite, PACE, is soon to be on the case!

Set to launch on Feb. 6, 2024, the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission will help us better understand the complex systems driving the global changes that come with a warming climate.

Earth’s ocean is becoming greener due to climate change. PACE will see the ocean in more hues than ever before.

While a single phytoplankton typically can’t be seen with the naked eye, communities of trillions of phytoplankton, called blooms, can be seen from space. Blooms often take on a greenish tinge due to the pigments that phytoplankton (similar to plants on land) use to make energy through photosynthesis.

In a 2023 study, scientists found that portions of the ocean had turned greener because there were more chlorophyll-carrying phytoplankton. PACE has a hyperspectral sensor, the Ocean Color Instrument (OCI), that will be able to discern subtle shifts in hue. This will allow scientists to monitor changes in phytoplankton communities and ocean health overall due to climate change.

Phytoplankton play a key role in helping the ocean absorb carbon from the atmosphere. PACE will identify different phytoplankton species from space.

With PACE, scientists will be able to tell what phytoplankton communities are present – from space! Before, this could only be done by analyzing a sample of seawater.

Telling “who’s who” in a phytoplankton bloom is key because different phytoplankton play vastly different roles in aquatic ecosystems. They can fuel the food chain and draw down carbon dioxide from the atmosphere to photosynthesize. Some phytoplankton populations capture carbon as they die and sink to the deep ocean; others release the gas back into the atmosphere as they decay near the surface.

Studying these teeny tiny critters from space will help scientists learn how and where phytoplankton are affected by climate change, and how changes in these communities may affect other creatures and ocean ecosystems.

Climate models are one of our most powerful tools to understand how Earth is changing. PACE data will improve the data these models rely on.

The PACE mission will offer important insights on airborne particles of sea salt, smoke, human-made pollutants, and dust – collectively called aerosols – by observing how they interact with light.

With two instruments called polarimeters, SPEXone and HARP2, PACE will allow scientists to measure the size, composition, and abundance of these microscopic particles in our atmosphere. This information is crucial to figuring out how climate and air quality are changing.

PACE data will help scientists answer key climate questions, like how aerosols affect cloud formation or how ice clouds and liquid clouds differ.

It will also enable scientists to examine one of the trickiest components of climate change to model: how clouds and aerosols interact. Once PACE is operational, scientists can replace the estimates currently used to fill data gaps in climate models with measurements from the new satellite.

With a view of the whole planet every two days, PACE will track both microscopic organisms in the ocean and microscopic particles in the atmosphere. PACE’s unique view will help us learn more about the ways climate change is impacting our planet’s ocean and atmosphere.

Stay up to date on the NASA PACE blog, and make sure to follow us on Tumblr for your regular dose of sPACE!

Did you know that there are 5 known dwarf planets in our solar system? Everyone knows Pluto, but there is also Ceres, Haumea, Makemake and Eris.

Info from: https://www.iau.org/public/themes/pluto/#n6

Comet Nishimura Credit: Peter Kennett

NASA Science

How Gravity Warps Light - NASA Science

Gravity is obviously pretty important. It holds your feet down to Earth so you don’t fly away into space, and (equally important) it keeps y

Article of the Day!

"How Gravity Warps Light" from NASA Universe Web Team

A personal item was found on the observatory decks the day after our public night. If you lost something, check with the Dean's office in the DMF Science and Math Center!

Wed. Nov. 15 - We will be closed tonight due to cloud cover.

Yuck: