Can the galaxy’s dead stars help us in our search for life? A group of researchers from Cornell University thinks so. They say that watching exoplanets transit in front of white dwarfs can tell us a lot about those planets.
This week we are pleased to welcome Dr. Merav Opher, Professor from the Astronomy Department of Boston University and the Director of the SHIELD (Solar wind with Hydrogen Ion charge Exchange and Large-Scale Dynamics) DRIVE Science Center. Using data from NASA’s planetary science missions, SHIELD scientists use data/computer modeling to predict the characteristics of our Sun’s heliosphere. Historically, the heliosphere has been thought to be comet-shaped. However, in a paper published in March, 2020, in Nature Astronomy, Dr. Opher (as lead author) and the team from SHIELD predict an alternative shape for the heliosphere: one that does not include this tail, but rather resembles a “deflated croissant.”
Astronomers Measure a 1-billion Tesla Magnetic Field on the Surface of a Neutron Star
We recently observed the strongest magnetic field ever recorded in the Universe. The record-breaking field was discovered at the surface of a neutron star called GRO J1008-57 with a magnetic field strength of approximately 1 BILLION Tesla. For comparison, the Earth’s magnetic field clocks in at about 1/20,000 of a Tesla – tens of trillions of times weaker than you’d experience on this neutron star…and that is a good thing for your general health and wellbeing.
Neutron stars are the “dead cores” of once massive stars which have ended their lives as supernova. These stars exhausted their supply of hydrogen fuel in their core and a power balance between the internal energy of the star surging outward, and the star’s own massive gravity crushing inward, is cataclysmically unbalanced – gravity wins. The star collapses in on itself. The outer layers fall onto the core crushing it into the densest object we know of in the Universe – a neutron star. Even atoms are crushed. Negatively charged electrons are forced into the atomic nuclei meeting their positive proton counterparts creating more neutrons. When the core can be crushed no further, the outer remaining material of the star rebounds back into space in a massive explosion – a supernova. The resulting neutron star, made of the crushed stellar core, is so dense that a single sugar-cube-sized sampling would weigh billions of tons – as much as a mountain (though if you’re “worthy” you MIGHT able to lift it since Thor’s Hammer is made of the stuff). Neutron stars are typically about 20km in diameter and can still be a million degrees Kelvin at the surface.
But if they’re “dead,” how can neutron stars be some of the most magnetic and powerful objects in the Universe?
In the beginning, the universe created three elements: hydrogen, helium, and lithium. There isn’t much you can do with these simple elements, other than to let gravity collapse them into stars, galaxies, and black holes. But stars have the power of alchemy. Within their hearts, they can fuse these elements into new ones. Carbon, nitrogen, oxygen, and others, all up to the heavy element of iron. When these first stars exploded, they scattered the new elements across the cosmos, creating planets, new stars, and even us.
Everything in space is moving. Galaxies collide and merge, massive clouds of gas migrate, and asteroids, comets, and rogue planets zip around and between it all. And in our own Solar System, the planets follow their ancient orbits.
Now a new data visualization shows us just how much our view from Earth changes in two years, as the orbits of the planets change the distance between us and our neighbours.
The discovery of phosphine in the upper clouds in Venus’ atmosphere has generated a lot of excitement. On Earth, phosphine is produced biologically, so it’s a sign of life. If it’s not produced by life, it takes an enormous amount of energy to be created abiologically.
On other planets like Jupiter, there’s enough energy to produce phosphine, so finding it there isn’t surprising. But on a small rocky world like Venus, where there’s no powerful source of energy, its existence is surprising.
Astronomer William Herschel discovered Uranus—and two of its moons—230 years ago. Now a group of astronomers working with data from the telescope that bears his name, the Herschel Space Observatory, have made an unexpected discovery. It looks like Uranus’ moons bear a striking similarity to icy dwarf planets.
The Herschel Space Observatory has been retired since 2013. But all of its data is still of interest to researchers. This discovery was a happy accident, resulting from tests on data from the observatory’s camera detector. Uranus is a very bright infrared energy source, and the team was measuring the influence of very bright infrared objects on the camera.
The images of the moons were discovered by accident.
Scientists have learned a lot about the atmospheres on various worlds in our Solar System simply from planetary sunrises or sunsets. Sunlight streaming through the haze of an atmosphere can be separated into its component colors to create spectra, just as prisms do with sunlight. From the spectra, astronomers can interpret the measurements of light to reveal the chemical makeup of an atmosphere.
As part of Project Artemis, NASA intends to send the first woman and the next man to the Moon by 2024, in what will be the first crewed mission to the lunar since the Apollo Era. By the end of the decade, NASA also hopes to have all the infrastructure in place to create a program for “sustainable lunar exploration,” which will include the Lunar Gateway (a habitat in orbit) and the Artemis Base Camp (a habitat on the surface).
Part of this commitment entails the recovery and use of resources that are harvested locally, including regolith to create building materials and ice to create everything from drinking water to rocket fuel. To this end, NASA has asked its commercial partners to collect samples of lunar soil or rocks as part of a proof-of-concept demonstration of how they will scout and harvest natural resources and conduct commercial operations on the Moon.