Category Astronomy/Space

Milky Way Family Tree

Family tree of the Milky Way. The main progenitor of the Milky Way is denoted by the trunk of the tree, coloured by stellar mass. Black lines indicate the five identified galaxies. Grey dotted lines depict other mergers that the Milky Way experienced that could not be connected to a specific progenitor. From left to right, the six images along the top of the figure indicate the identified progenitor galaxies: Sagittarius, Sequoia, Kraken, the Milky Way’s Main progenitor, the progenitor of the Helmi streams, and Gaia-Enceladus-Sausage. | © D. Kruijssen

Astrophysicists reconstruct the galaxy merger history of our home galaxy. Galaxies like the Milky Way formed by the merging of smaller progenitor galaxies...

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Astronomers discover New ‘Fossil Galaxy’ Buried Deep within the Milky Way

An all-sky image of the stars in the Milky Way as seen from Earth. The coloured rings show the approximate extent of the stars that came from the fossil galaxy known as Heracles. Credit: Danny Horta-Darrington (LJMU), ESA/Gaia, SDSS

Scientists working with data from the Sloan Digital Sky Surveys’ Apache Point Observatory Galactic Evolution Experiment (APOGEE) have discovered a “fossil galaxy” hidden in the depths of our own Milky Way. This result, published in Monthly Notices of the Royal Astronomical Society, may shake up our understanding of how the Milky Way grew into the galaxy we see today.

The proposed fossil galaxy may have collided with the Milky Way ten billion years ago, when our galaxy was still in its infancy...

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Field Geology at Mars’ Equator Points to Ancient Megaflood

Mars environment
This composite, false-color image of Mount Sharp inside Gale crater on Mars shows geologists a changing planetary environment. On Mars, the sky is not blue, but the image was made to resemble Earth so that scientists could distinguish stratification layers.

Floods of unimaginable magnitude once washed through Gale Crater on Mars’ equator around 4 billion years ago — a finding that hints at the possibility that life may have existed there, according to data collected by NASA’s Curiosity rover and analyzed in joint project by scientists from Jackson State University, Cornell University, the Jet Propulsion Laboratory and the University of Hawaii.

The research, “Deposits from Giant Floods in Gale Crater and Their Implications for the Climate of Early Mars,” was published Nov...

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Newborn Jets in Distant Galaxies – Jets ‘turned on’ in past two decades or so.

Credit: Sophia Dagnello, NRAO/AUI/NSF

Comparing data from VLA sky surveys made some two decades apart revealed that the black hole-powered ‘engines’ at the cores of some distant galaxies have launched new, superfast jets of material during the interval between the surveys.

Astronomers using data from the ongoing VLA Sky Survey (VLASS) have found a number of distant galaxies with supermassive black holes at their cores that have launched powerful, radio-emitting jets of material within the past two decades or so. The scientists compared data from VLASS with data from an earlier survey that also used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to reach their conclusion.

“We found galaxies that showed no evidence of jets before but now show clear indicati...

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