Latest Posts:
Moon or Bust, Part 1
Between 1969 and 1972, twelve men, all Americans, walked on the surface of the moon. No one has returned since Gene Cernan climbed back into the Challenger lunar lander on December 14, 1972. When will people return? And what might be their nationality?
In the 1960s, the race to the moon had two contestants: the United States and the Soviet Union. In the 2020s and beyond, the only real...read more ❯
Rocket Juice, Part 2
It takes a lot of energy to get a rocket into space. That energy comes in the form of its propellant, a catch-all term that includes both fuel and oxidizer. There is no oxygen available to burn the fuel in the vacuum of space; we can’t ignite a solid fuel and rely on air to provide the oxygen, the way we can with a model rocket here on...read more ❯
Shadows in the Night
Three time periods: 29.4 years, 14.7 years (half the previous number), and 16 days. What do these numbers represent, and how are they connected?
In an earlier Star Struck post, we talked about how the tilt of Saturn’s rings changes their appearance as seen from Earth.
Saturn orbits the Sun every 29.4 years, and twice during that time, every 14.7 years, its rings appear edge on to...read more ❯
ET Found! What Now?
More than fourteen years ago, I wrote a post about the Drake Equation, a way of thinking about how likely it might be that we could communicate with extraterrestrial intelligence. Near the end of that, I wrote the following.
The implications of finding life of any sort, much less intelligent, communicating life, are simply enormous. In my next post, I want to talk about what some of those...read more ❯
Tilt!
Whenever I’ve had the privilege of showing a telescopic view of Saturn to someone who has never seen it before, the almost inevitable response is disbelief. “Is that real?” Especially if its beautiful rings are highly tilted, the view is among the most beautiful objects in our solar system. This is an image I took a few years ago at the Belk Observatory, on the grounds of the Claytor Nature...read more ❯
Mirror, Mirror
The first telescopes, like the ones Galileo used to discover the moons of Jupiter and craters on the moon, were crude by today’s standards. Nonetheless, they were gateways to a new understanding of our place in the cosmos.
All telescopes are what I like to describe as light funnels. Their function is to gather more light than can naturally pass through your eye’s pupil, with its 6 to 7...read more ❯
Strange Visitor from Another Star
It’s a bird! It’s a plane! No, it’s 3I/ATLAS, the third known object to visit our solar system from outside it. The “3” in the name indicates that it is the third such object, the “I” that it is interstellar, and the “ATLAS” that it was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile. Although that telescope was designed...read more ❯
More Rocket Science
Take a look at these two images, both the tail end of the first stage of a really big rocket. One is from almost sixty years ago. The other is contemporary. Both have a lot of rocket engines designed to work together. Can you tell which is which?
OK, the graininess of that first image may have given it away. Those 30 engines are on the first stage of the N-1 rocket, the rocket that the...read more ❯
It's Not Rocket Science
The basics of rocket science really are pretty simple. Send a lot of hot gas out one end of a rocket, and it will go in the opposite direction. You know what’s hard? Orbital mechanics, maneuvering a spacecraft to rendezvous with something else. Or at the very least, it’s counterintuitive.
On June 3rd in 1965, the Gemini 4 mission was launched, with Jim McDivitt and Ed White as the...read more ❯
Location, Location, Location
Why does SpaceX launch its gigantic Starship from as far south as you can get in Texas?
Is it because Elon Musk likes lower taxes and a looser regulatory environment than he might find in other states? Probably. But there are very good technical reasons why orbital launch facilities are generally situated close to the equator. American rockets lift off from Cape Canaveral in Florida, at...read more ❯