Extract from ABC News
NASA/ESA's ultra powerful Hubble Space Telescope has delivered an image of a 'galactic dance' between three galaxies hundreds of millions of light years away from earth.
Launched in 1990, the Hubble Space Telescope can detect objects that are 10 billion times fainter than the unaided eyes can see.
Okay, what am I looking at?
The below image shows galaxies that lie roughly 500 million light years away from earth in the constellation Tucana.
There are two clearly defined galaxies in the image: NGC 7733 is the smaller one on the lower right and NGC 7734 is the larger one in the top left.
They are an interacting galaxy pair know as Arp-Madore 2339-661.
But if you look closely, you'll see that there are not only two galaxies in this image — there are three.
Nestled between the two galaxies — just above the upper arm of NGC 7733 — is a knot-like structure glowing with a different colour and obscured by dark dust.
While this might seem like a part of the NGC 7733 galaxy, NASA's analysis of its speed and direction reveal that it's very likely an entity of its own.
The Hubble image shows all three galaxies interacting gravitationally with one another.
NASA says this kind of galaxy interaction is sometimes referred to as 'merging groups', which means they could ultimately become a single entity.
New molten Mars layer uncovered by NASA lander
Despite being retired in 2022, NASA's InSight lander is still providing data that unveils mysteries about the Red Planet.
New seismic data from the lander indicates the presence of a hitherto unknown layer of molten rock surrounding a liquid metallic core — the planet's innermost component — that is smaller and denser than previously estimated, researchers said.
Waves generated by quakes — including those caused by meteorite impacts — vary in speed and shape when journeying through different material inside a planet.
Data from InSight's seismometer instrument has enabled the planet's internal structure to come into focus.
The meteorite impact that occurred in a Martian highland region called Tempe Terra on September 18, 2021, triggered a magnitude-4.2 quake and left a crater about 130 meters wide.
It occurred on the opposite side of Mars from InSight's location in a plains region called Elysium Planitia.
The behaviour of the waves indicated that previous assessments of the Martian interior were missing something — the presence of a molten silicate layer about 150km thick surrounding the core.
This molten region sits at the bottom of the interior portion of the planet called the mantle.
The researchers also recalculated the size of the core, finding it has a diameter of about 3,350km.
The researchers said the mantle — a rocky layer sandwiched between the planet's outermost crust and core — extends about 1,700km below the surface.
Unlike Mars, Earth has no molten layer around its core.
One of the two studies published on Wednesday indicates this layer is fully molten, with the other indicating that most of it is fully molten, with the top portion partially molten.
ABC/Reuters
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