SUNSET: 
Cosmic Relief with David Grinspoon
Can a Planet Think? The Gaia Hypothesis, Rethought
Humans have irrevocably changed the planet. Have those processes gone so far that Earth’s biosphere has begun to resemble a human brain?
Cosmic Relief with David Grinspoon
One Small Step for Plantkind
With a seed germinated on the lunar farside, Earth’s biosphere made its first tentative foray into the cosmos.
Cosmic Relief with David Grinspoon
Sudden Impact: What Greenland's Crater Means for Our Planet's History
The discovery of a recent huge meteor crater beneath Greenland’s ice sheet has reignited a debate over cosmic influences.
Cosmic Relief with David Grinspoon
NASA Renews Interest in SETI
After a long hiatus, NASA gets back into the SETI game with a workshop on “technosignatures.”
Cosmic Relief with David Grinspoon
Clouds: A Nebulous Existence
In David Grinspoon's latest column, he discusses how, for both Venus and Earth, life's last refuge might lie in the clouds.
Cosmic Relief with David Grinspoon
Variations on a Theme: What Do Earth and Pluto Share in Common?
Nature loves to riff on existing motifs, even in the most unearthly of environments.
Cosmic Relief with David Grinspoon
Advancing the SETI Quest
Hope, perseverance, and the courage of their convictions sustain those seeking hints of alien civilizations and advancing the SETI quest.
Cosmic Relief with David Grinspoon
Chipping Away at Exoplanets
Human ingenuity is helping us unlock the secrets of unimaginably distant worlds — exoplanets.
Cosmic Relief with David Grinspoon
Cosmic Communion: A Total Solar Eclipse
Last summer's total solar eclipse provided a profound moment of celestial accord for millions of Americans.
Cosmic Relief with David Grinspoon
Life Outside the Habitable Zone
What would allow a planet to host life? The habitable zone is often defined as the distance from a star where liquid water can exist on a planet's surface.
Cosmic Relief with David Grinspoon
Not Venus Again
Once more, NASA leaves our sister planet out of the mix of new missions. Ouch.
Cosmic Relief with David Grinspoon
Mars and Our Expectations
The Red Planet has inspired a long history of brilliant mistakes.
Cosmic Relief with David Grinspoon
Thank Our Lucky Planets: How Planets Really Do Shape Our Fate
Human history has always been linked to the influence of distant orbits, from climate change (past and present) to our exploration of the solar system.
Cosmic Relief with David Grinspoon
Mars Reconnaissance Orbiter: Ten Years Over Mars
It’s easy, but wrong, to take for granted a mission that’s still going strong after a decade.
Cosmic Relief with David Grinspoon
The Golden Spike of Tranquility Base
A modest proposal: the golden spike that marked the beginning of the Anthropocene was the first lunar landing in Mare Tranquilitatis.
Cosmic Relief with David Grinspoon
International Space Station: Our Year In Space
ISS astronauts are reviving our passion for space travel in novel ways.
Cosmic Relief with David Grinspoon
Could It Be: Possible Signs of Extraterrestrial Intelligence?
We need to learn how to talk about possible signs of extraterrestrial intelligence.
Cosmic Relief with David Grinspoon
No Need to Feel Lonely
Are we alone in the universe? Recent results don't support that conclusion, despite what the headlines say.
Cosmic Relief with David Grinspoon
Farewell to a Friend
After a tremendously successful mission, Venus Express has orbited its last.
Cosmic Relief with David Grinspoon
Sidewalk Wisdom: Isaac Asimov on Biology
Musing on a long-lost Asimov gem.