Harold Geller (@AstroBioProf) header
Harold Geller (@AstroBioProf) profile picture

Harold Geller

@AstroBioProf

GMU Associate Professor Emeritus; NASA/JPL Solar System Ambassador (volunteer). Opinions are my own. Links are not endorsements.

 Fairfax, Virginia
physics.gmu.edu/~hgeller/
Joined February 2009
  • Tweets54.2K
  • Following7.6K
  • Followers8.4K
5.8KMedia
Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)Photo by Harold Geller (@AstroBioProf)
14th Anniversary of the George Mason University Observatory telescope installed 10 May 2011. See youtube.com/watch?v=j6OqmsR5…
1
2
4
849
"November 6 and 7 mornings: Venus has returned!" see earthsky.org/astronomy-essen…
Visible planets and night sky guide for November

Visible planets and night sky guide for November

Visible planets and night sky guide. Tomorrow morning, the moon will hang close to Mars, Jupiter and Regulus. And watch for Taurid meteors!

earthsky.org
43
"The Most Abused Logical Fallacies" by @BrianDunning see: skeptoid.com/episodes/1065
The Most Abused Logical Fallacies - Skeptoid

The Most Abused Logical Fallacies - Skeptoid

Some common logical fallacies frequently misused or misdefined — and how to use them properly.

skeptoid.com
32
"How Trump Is Dismantling America’s Scientific Research Machine" see nytimes.com/2026/10/31/scien…
How Trump Is Dismantling America’s Scientific Research Machine

How Trump Is Dismantling America’s Scientific Research Machine

The system that has driven life-altering discoveries and helped make the United States a superpower is now under intense strain.

nytimes.com
1
1
53
"I Used AI to Fake a Scientific Paper. Here’s What Happened" see spectrum.ieee.org/ai-generat…
I Tried to Fool a Scientific Publisher With AI

I Tried to Fool a Scientific Publisher With AI

My experiment with an IEEE journal revealed AI’s threats to scholarly publishing

spectrum.ieee.org
52
"Can a Radioactive Ore Break China’s Grip on Rare Earths?" see spectrum.ieee.org/monazite-r…
Heavy Mineral Sands Are Quietly Rewriting Rare Earth Supply Chains

Heavy Mineral Sands Are Quietly Rewriting Rare Earth Supply Chains

Monazite ore holds the key to powerful motor magnets—if we can handle it

spectrum.ieee.org
29
"The Robot I Didn’t Expect to Build" see spectrum.ieee.org/agility-ro…
The Robot I Didn’t Expect to Build

The Robot I Didn’t Expect to Build

Agility Robotics’ first practical robotic worker is nothing like I dreamed

spectrum.ieee.org
30
"November is here. And what a great month it is, for both planets and meteor showers!" see youtube.com/watch?v=LOIbwoMr…
Best Night Sky Forecast For November 2026

Best Night Sky Forecast For November 2026

November is here. And what a great month it is, for both planets an...

youtube.com
64
"Did the Viking 2 lander detect marsquakes in 1976?" See earthsky.org/space/marsquake…
Did the Viking 2 lander detect marsquakes in 1976?

Did the Viking 2 lander detect marsquakes in 1976?

New analysis shows that 2 possible marsquakes detected by Viking 2 were in the same region as nearly 1,000 others detected by the InSight lander decades later.

earthsky.org
32
"Did comets seed life on Earth? A new study says — probably not" see earthsky.org/space/did-comet…
Did comets seed life on Earth? A new study says — probably not

Did comets seed life on Earth? A new study says — probably not

Did comets seed life on Earth? It's unlikely, a new study from the University of Cambridge says. It would have been a very rare occurrence.

earthsky.org
49
"Kennedy to select MAHA-aligned researcher to head mental health institute, overruling NIH director" see science.org/content/article/…
Kennedy to select MAHA-aligned researcher to head mental health institute, overruling NIH director

Kennedy to select MAHA-aligned researcher to head mental health institute, overruling NIH director

Health secretary wants a leader of “metabolic psychiatry” movement to direct $2.2 billion agency

science.org
74
"Why does anything exist? New theory emerges" see earthsky.org/space/why-does-…
Why does anything exist? New theory emerges

Why does anything exist? New theory emerges

Why does anything exist? A new theory suggests a forgotten particle might have shifted the balance between matter and antimatter.

earthsky.org
1
67
"Stars brewing in a nebulous cauldron" see esa.int/ESA_Multimedia/Image…
49
"Multi-Cancer Detection: Panacea or Problem?" @BrianDunning see skeptoid.com/episodes/1063
Multi-Cancer Detection: Panacea or Problem? - Skeptoid

Multi-Cancer Detection: Panacea or Problem? - Skeptoid

These tests that promise to easily detect cancer with a blood test are fraught with profound accuracy errors.

skeptoid.com
56
"Orionid meteor shower 2026: All you need to know" see earthsky.org/astronomy-essen…
Orionid meteor shower 2026: All you need to know

Orionid meteor shower 2026: All you need to know

The Orionid meteor shower peaks on October 21! Find out the best time to watch, where to look in the sky and how to spot meteors with our charts and tips.

earthsky.org
25
"MMX lifts off to Mars’s moon Phobos" see esa.int/ESA_Multimedia/Image…

MMX lifts off to Mars’s moon Phobos

MMX lifts off to Mars’s moon Phobos

esa.int
48
"The MMX mission launches to Mars’ moons on Monday" see earthsky.org/space/mmx-missi…
The MMX mission launches to Mars’ moons on Monday

The MMX mission launches to Mars’ moons on Monday

The MMX mission launches October 19 to Mars’ moons Phobos and Deimos. It will collect a sample from Phobos and return it to Earth in 2031.

earthsky.org
117
AI and nuclear energy, see spectrum.ieee.org/ai-assista…
AI Steps Into Nuclear Power Plants, and Workers Are Letting It in

AI Steps Into Nuclear Power Plants, and Workers Are Letting It in

AI assistants can help a shrinking specialized workforce maintain aging power plants

spectrum.ieee.org
54
"Measure Distant Asteroids With a DIY Rig" see spectrum.ieee.org/asteroid-s…
Measure An Asteroid’s Shadow With a Small Telescope and Some DIY Gear

Measure An Asteroid’s Shadow With a Small Telescope and Some DIY Gear

Watching space rocks obscure stars is easier than you think

spectrum.ieee.org
41
"The 80-year nuclear legacy in the Marshall Islands - Physics Today" see doi.org/10.1063/pt.29b43e112…
The 80-year nuclear legacy in the Marshall Islands

The 80-year nuclear legacy in the Marshall Islands

An interview with a prominent member of the Marshallese diaspora delves into the ongoing impact of aboveground US nuclear weapons testing in the Pacific archipelago.

physicstoday.aip.org
44
"A quantum leap for Virginia" see gmu.edu/news/2026-10/podcast…
Podcast: A quantum leap for Virginia

Podcast: A quantum leap for Virginia

President Gregory Washington is joined by TreQ founder and CEO Mandy Birch and director of George Mason's Quantum Science and Engineering Center Patrick Vora to discuss establishing the Virginia...

gmu.edu
48
Load more