Researchers at NASA's Jet Propulsion Laboratory in Pasadena, California, are cooking up an alien atmosphere right here on Earth. In a new study, JPL scientists used a high-temperature "oven" to heat a mixture of hydrogen and carbon monoxide to more than 2,000 degrees Fahrenheit (1,100 Celsius), about the temperature of molten lava. The aim was to simulate conditions that might be found in the atmospheres of a special class of exoplanets (planets outside our solar system) called "hot Jupiters."
Shortly after the big bang, the universe was an energetic mixture of particles with strong mutual interaction. The first particles that managed to free themselves from this dense primordial soup were the neutrinos, the lightest and weakest interacting particles from the standard model of elementary particles. These neutrinos are still all around us today, but are very difficult to observe immediately because their interaction is so weak. An international team of cosmologists, including Daniel Baumann and Benjamin Wallisch from the University of Amsterdam, has now succeeded in measuring the influence that this 'cosmic neutrino background' has had on the way galaxy clusters formed during the evolution of the universe. The research was published in Nature Physics.
When stars like our Sun exhaust their hydrogen fuel, they enter what is known as their Red-Giant-Branch (RGB) phase. This is characterized by the star expanding to several times it original size, after which they shed their outer layers and become compact white dwarfs. Over the next few billion years, it is believed that these stars will slowly consume any objects and dust rings still close enough to be influenced by their gravity.
In this image, the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top center of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth.
Astronomers have known for some time that the Milky Way and the Andromeda galaxies will collide on some future date. The best guess for that rendezvous has been about 3.75 billion years from now. But now a new study based on Data Release 2 from the ESA’s Gaia mission is bringing some clarity to this future collision.
According to widely-accepted theories, the Solar System formed roughly 4.6 billion years ago from a massive cloud of dust and gas (aka. Nebular Theory). This process began when the nebula experienced a gravitational collapse in the center that became our Sun. The remaining dust and gas formed a protoplanetary disk that (over time) accreted to form the planets.
For some small minority of humans, Death By Asteroid is a desirable fate. The idea probably satisfies their wonky Doomsday thinking. But for the rest of us, going out the same way the dinosaurs did would just be embarrassing. Thankfully, the ESA’s Hera mission will visit the smallest spacerock ever, and will help us avoid going the way of the dinosaurs.
Scientists have been searching for “dark matter” – an unknown and invisible substance thought to make up the vast majority of matter in the universe – for nearly a century. The reason for this persistence is that dark matter is needed to account for the fact that galaxies don’t seem to obey the fundamental laws of physics. However, dark matter searches have remained unsuccessful.
How fast is the Universe expanding? That’s a question that astronomers haven’t been able to answer accurately. They have a name for the expansion rate of the Universe: The Hubble Constant, or Hubble’s Law. But measurements keep coming up with different values, and astronomers have been debating back and forth on this issue for decades.
When exploring other planets and celestial bodies, NASA missions are required to abide by the practice known as “planetary protection“. This practice states that measures must be taken during the designing of a mission to ensure that biological contamination of both the planet/body being explored and Earth (in the case of sample-return missions) are prevented.
Our understanding of the universe, and of the Milky Way, is built on an edifice of individual pieces of knowledge, all related to each other. But each of those pieces is only so accurate. The more accurate we can make one of the pieces of knowledge, the more accurate our understanding of the whole thing is.
Astronomers theorize that when our Sun was still young, it was surrounded by a disc of dust and gas from which the planets eventually formed. It is further theorized that the majority of stars in our Universe are initially surrounded in this way by a “protoplanetary disk“, and that in roughly 30% of cases, these disks will go on to become a planet or system of planets.
About fifty years ago, astronomers predicted what the ultimate fate of our Sun will be. According to the theory, the Sun will exhaust its hydrogen fuel billions of years from now and expand to become a Red Giant, followed by it shedding it’s outer layers and becoming a white dwarf. After a few more billion years of cooling, the interior will crystallize and become solid.