Jun 12
El volumen total del sol es de 1,4 x 1027 metros cúbicos. Aproximadamente 1,3 millones de Tierras podrían caber dentro del sol. La masa del sol es de 1,989 x 1030 kilogramos, aproximadamente 333.000 veces la masa de la Tierra.
Jun 9
Jun 7
Visited the planetarium near the Hollywood sign
Jun 6
The research was overseen by the Institutional Review Board, which is what I named my surfboard.
Planetary Science [Explained]
Transcript
[An article from a journal is shown.]
[Title of journal article:] Evidence for Liquid Water on the Surface of a Terrestrial Planet in the Habitable Zone
[Below the title are four lines of blurred text presumably representing the name of the author or authors and their affiliations. Below that, the text of the article is blurred, displayed in two columns. There are three sections of blurred text each with a blurred boldface heading. Two pictures are included amid the blurred text. The picture in the left column shows the sea running alongside a beach. The picture in the right column shows Jill and Kidball playing at the beach, with Jill running and Kidball building a sandcastle, while Cueball and Megan are sitting under a beach umbrella watching them.]
[Caption below the article:] Planetary science journals have asked astronomers to please stop submitting their vacation photos.
Jun 5
(via xkcd: Planetary Science)
Jun 2
The rotation of a protoplanetary disk (a disk where planets are being formed) has been observed directly for the very first time by mapping
"The rotation of a protoplanetary disk (a disk where planets are being formed) has been observed directly for the very first time by mapping the emissions from the dust grains within it. The disk in question surrounds the young star AB Aurigae. Although it appears to generally rotate in accordance with the laws of physics, certain regions close to the star show an unexpected departure from this behavior. A body of evidence suggests that this anomaly is caused by the presence of giant planets in the process of formation.
(The protoplanetary disc of AB Aurigae. Credit: ESO)
The study, led by scientists from the CNRS and the University of Bordeaux is published in the journal Astronomy & Astrophysics. It sheds fresh light on the mechanisms of planetary formation and the complex dynamics of protoplanetary disks.
Thanks to the unique near-infrared capabilities of the SPHERE instrument and its exceptional spatial resolution, the team was able to accurately track the disk's structures and their evolution during three sets of observations, collected over a 4-year period. The scientists identified a bright structure, characteristic of accretion zones where gas and dust accumulate and fall onto an object in the process of formation. This phenomenon is closely linked to the formation of gas giant planets."
continue reading article
Jun 1
All's well that ends without an explosion.
I'm talking about what I think is a very ambitious project by NASA which is to place a nuclear reactor on the Moon by 2030. And we're not the only ones who have such plans—now China & Russia also want to have a nuclear reactor on the Moon, but by 2030. NASA & the U.S. Dept. of Defense (DoD) have formally committed to deploying a fission surface power reactor on the Moon within 4 years. They signed an MOU (memorandum of understanding) to develop, fuel, authorize & prepare the system. Once established, it should provide continuous power for years without refueling. The nuclear generator will be truck-sized so that a lunar base doesn't freeze or go dark during the 14-day lunar night. The power for continuous fission (the splitting of atoms as opposed to fusion, the joining of atoms) will range from a 100 kW continuous fission system (enough power to run 30 homes) to 500 kW (enough power to run 150 homes). They plan to use their lunar base for mining, erect a launchpad & establish a habitat complex for the "Moonies," all of which will require 1-10 MW (megawatt) scale power, which is 1,000 times more than a kW.
Energy will be needed to extract oxygen from regolith (the layer of rocky material that covers the lunar surface). Inside regolith there are metal oxides (about 43% by weight), from which oxygen can be extracted. Energy will be needed to mine & process metals, to operate launchers & to run rovers, drills, life support, comms & cryocoolers. The problem is that unlike Earth, where reactors dump heat into air or water, on the Moon, there is no air or water. The solution? Large thermal radiators that radiate heat away as infrared light. They will have to coat the radiators with dust-resistant shields because lunar dust is razor-sharp. The dust clogs radiators, scratches surfaces, & jams moving parts. Rather than ship fuel back and forth from the Earth to the Moon, the plan is to send the reactor already loaded with highly enriched, long-life fuel, like a long-life battery.
Other challenges include the Moon's extreme temperatures (-410°F to +250°F / -246°C to +121°C). Moonies will have to endure constant tiny high-speed micrometeorite impacts that can puncture radiators, cables & shielding. Imagine living on the Moon & being sandblasted by BB gun pellets that travel faster than bullets. The Moon has regular shallow earthquakes that can last for hours. Humans will, of course, need shielding from radiation, & electronics & reactor components will need to be protected. Shielding for the reactor is heavy & will be costly to launch. High-voltage cables will need protection from the harsh lunar environment. NASA scientists & engineers will have to guarantee the nuclear core stays safe even if the rocket explodes, because a crash could scatter radioactive material.
They'll have to ensure there is a sufficient supply of spare parts—even if a $5.00 bolt breaks, you don't want to send a $2 billion rocket to deliver a new one. They will have to design a brand new class of lunar reactors. No reactor has ever run in lunar gravity, vacuum, dust, or extreme temperature cycles. It's not a "copy-paste" from Earth—it's inventing a whole new machine. The reactor must endure a roller coaster from hell before it reaches space. Robots will be needed to unfold radiators, connect cables & activate systems autonomously. Every challenge above adds a delay risk. My assessment is a 60-70% likelihood of a prototype reactor being delivered to the lunar surface by 2030-2032. It's more likely to slip somewhere in the mid-2030s.
As for the joint Russia-China goal of 2035, I give it a 50-60% likelihood of a lunar reactor by 2035-2037. They face the same challenges, & Russia's economy is suffering in large part because of the war in Ukraine. But sooner or later, from one nation or another, nuclear power on the Moon will happen. This is the new space race & whoever controls lunar energy will control the lunar industry.
