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 ❯
Where Does Space Begin?
If you are old enough, like me, to remember when riding a rocket into space was something no one had ever done, you may be joining me in some mix of amusement, mild disdain, and (let’s face it) jealousy at all the millionaires and celebrities, and a few regular folks, who get to do so.
As of this writing, Jeff Bezos’ New Shepard rocket is scheduled to carry six persons on an 11-minute ride...read more ❯
Twins, Siblings, and Only Children
Many people have at least a passing interest in astronomy. It’s why, even though my graduate education is in chemistry, I’m always sure to tell new acquaintances that I taught astronomy for much of my career. Chemistry is probably more obviously relevant to them, but astronomy is more popular.
Something they may have heard somewhere along the way is that the majority of stars are binaries,...read more ❯
Theories and Observations
I’m old enough to remember when the solar system was described as a fairly well-ordered place. There was the Sun, the rocky inner planets, an asteroid belt of smaller rocky objects, four large gaseous/icy planets, the since demoted Pluto, and smaller icy objects beyond the most distant currently recognized planet Neptune, from which comets originated. All of these objects were presumed to have...read more ❯
A New Moon Race?
When the Apollo astronauts landed on the moon between 1969 and 1972, they all landed fairly close to the lunar equator.
The largest excursion north or south was that of the Apollo 15 mission. It landed 26 degrees north of the equator in the Hadley–Apennine region, almost to the rim of Hadley Rille, hypothesized to be a collapsed lava tube.
The orbital mechanics of the Apollo...read more ❯
Perihelion Day
On January 4th, 2025 at 8:28 a.m. EST, Earth will reach perihelion, the point in its orbit when it is closest to the sun. Then why is it so cold, at least in the northern hemisphere?
Winter—indeed all seasons—don’t depend on the distance from the sun. If they did, then Australia would celebrate the Christmas season with snow instead of visits to the beach. Seasons are due to the axial...read more ❯
Rocket Science: Simple and Not So Simple
Rocket science at its most basic is surprisingly simple. If you throw enough stuff fast enough out the back of your rocket, it will make the rocket go forward. The more stuff you throw out and the faster you throw it, the faster your rocket will go.
If you’ve ever blown up a balloon and then let it go, you’ve seen this in action.
https://www.youtube.com/shorts/BDFlO_otiGk
But this...read more ❯
Meteor Showers 2024
For most people, if they are aware of a meteor shower, it is the Perseid shower in August. It’s pretty reliable, and it takes place at a time of year when being outside in the wee hours of the morning is actually pleasant.
But meteor showers occur at predictable times throughout the year, and there are some good ones coming this month and next. They are due to a comet (or rarely, an...read more ❯