What Are Brown Dwarfs?

Decoding Nebulae

We can agree that nebulae are some of the most majestic-looking objects in the universe. But what are they exactly? Nebulae are giant clouds of gas and dust in space. They’re commonly associated with two parts of the life cycle of stars: First, they can be nurseries forming new baby stars. Second, expanding clouds of gas and dust can mark where stars have died.

Not all nebulae are alike, and their different appearances tell us what's happening around them. Since not all nebulae emit light of their own, there are different ways that the clouds of gas and dust reveal themselves. Some nebulae scatter the light of stars hiding in or near them. These are called reflection nebulae and are a bit like seeing a street lamp illuminate the fog around it.

In another type, called emission nebulae, stars heat up the clouds of gas, whose chemicals respond by glowing in different colors. Think of it like a neon sign hanging in a shop window!

Finally there are nebulae with dust so thick that we’re unable to see the visible light from young stars shine through it. These are called dark nebulae.

Our missions help us see nebulae and identify the different elements that oftentimes light them up.

The Hubble Space Telescope is able to observe the cosmos in multiple wavelengths of light, ranging from ultraviolet, visible, and near-infrared. Hubble peered at the iconic Eagle Nebula in visible and infrared light, revealing these grand spires of dust and countless stars within and around them.

The Chandra X-ray Observatory studies the universe in X-ray light! The spacecraft is helping scientists see features within nebulae that might otherwise be hidden by gas and dust when viewed in longer wavelengths like visible and infrared light. In the Crab Nebula, Chandra sees high-energy X-rays from a pulsar (a type of rapidly spinning neutron star, which is the crushed, city-sized core of a star that exploded as a supernova).

The James Webb Space Telescope will primarily observe the infrared universe. With Webb, scientists will peer deep into clouds of dust and gas to study how stars and planetary systems form.

The Spitzer Space Telescope studied the cosmos for over 16 years before retiring in 2020. With the help of its detectors, Spitzer revealed unknown materials hiding in nebulae — like oddly-shaped molecules and soot-like materials, which were found in the California Nebula.

Studying nebulae helps scientists understand the life cycle of stars. Did you know our Sun got its start in a stellar nursery? Over 4.5 billion years ago, some gas and dust in a nebula clumped together due to gravity, and a baby Sun was born. The process to form a baby star itself can take a million years or more!

After billions more years, our Sun will eventually puff into a huge red giant star before leaving behind a beautiful planetary nebula (so-called because astronomers looking through early telescopes thought they resembled planets), along with a small, dense object called a white dwarf that will cool down very slowly. In fact, we don’t think the universe is old enough yet for any white dwarfs to have cooled down completely.

Since the Sun will live so much longer than us, scientists can't observe its whole life cycle directly ... but they can study tons of other stars and nebulae at different phases of their lives and draw conclusions about where our Sun came from and where it's headed. While studying nebulae, we’re seeing the past, present, and future of our Sun and trillions of others like it in the cosmos.

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Hiking to the largest Ammonite in the world!

Video description:

Titanites lived during the Late Jurassic Period and had a shell diameter of around 137 centimetres! surprisingly it wasn’t the largest ammonoid, as some species such as Parapuzosia could get over twice as large!

There were also some plant fossils around the area of this site!

I love the fact that a group of crows is called a "Murder" and a group of ravens is a "Conspiracy"

Jupiter Auroras by NASA Hubble

These Are The Oldest Footprints On Earth

Found on a prehistoric sea floor, the oldest footprints ever found were left between 551 million and 541 million years ago during the Ediacaran period. That is hundreds of millions of years before the dinosaurs.

The trackways tell scientists it was left by a bilaterian animal — that is, a creature with bilateral symmetry that has a head at one end, a back end at the other, and a symmetrical right and left side. Its paired appendages, scientists did not call them legs, were used to raise the animal off the sea floor as it moved.

Helicoprion: What if, like, teeth,

Mesosaurus: Yeah?

Helicoprion: but WHEEL

Mesosaurus: No don't -

Helicoprion:

(Image by ДиБгд)

Sliver of Saturn by NASA’s Marshall Space Flight Center

Cover design for an Italian reprint of Isaac Asimov’s “Foundation Trilogy” by Gabriel Björk Stiernström. 

Created using still images taken by the Cassini spacecraft during it’s flyby of Jupiter and while at Saturn. Shown is Io and Europa over Jupiter’s Great Red Spot.

NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill