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…
Category: Solar System
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…
Mars Is Ready For Its Closeup
Why does something look big? Is it because it actually IS big, or is it because it is close to us? The closest celestial body to the Earth is our Moon. It’s an object that’s very easy to see without…
Venus
I have often joked that when I am asked a question that begins with “I saw this really bright thing in the sky…” my answer has a 90% chance of being right if I just say “Venus.” It is the…
Tagged with: Venus
The Demotion of Pluto
Poor Pluto! It used to be a planet, and now it’s not. The underdog of the solar system is championed by fourth graders and Boomer traditionalists alike. When I give talks on astronomy, one of the most common questions I…
Killer Asteroids From Outer Space!
Q: Why are dinosaurs extinct? A: Because they didn’t have a space program. 66 million years ago an asteroid that was at least six miles wide smashed into what is now the Yucatan Peninsula. Releasing the energy of five billion…
Invasion From Earth!
Three spacecraft launched last summer will all arrive at Mars soon. The first is the United Arab Emirates’ Hope mission, which will begin firing its rocket engine to go into Mars orbit at 10:30 a.m. EST on Tuesday, February 9th.…
Finding Your Way In Space
Does anyone still know how to read a paper map in the era of GPS? I will confess that although I could use such a map for travel, I seldom do so. I love maps, and my home office has…
The Stuff Planets Are Made Of
Of what does our solar system consist? There are the big and obvious things: the sun, the planets, and the moons which orbit those planets. The cloud of gas and dust from which all this condensed 4.6 billion years ago…
The Great Conjunction
Our night sky appears to us like an overarching dome sprinkled with bright points of light. Some of those points of light appear to be very close to each other, and indeed the ancients envisioned the stars as all being…
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