Science & Discovery
Space science and discovery from Cosmic Herald — planetary science, cosmology, astrobiology, and the search for life beyond Earth.
-
Science & Discovery
The Oort Cloud is the solar system's outer shell. We've never directly observed it.
The Oort Cloud — a spherical shell of icy bodies at distances up to 100,000 AU from the Sun — is inferred from the orbits of long-period comets. It may contain trillions of objects and is thought to be the source of most comets that visit the inner solar system.
-
Science & Discovery
Saturn's rings exist because of a mathematical boundary. Anything inside it cannot hold itself together.
The Roche limit is the distance at which a planet's tidal forces overcome a satellite's self-gravity, preventing it from accreting or tearing it apart. Saturn's rings sit inside this boundary for water ice, which is why they exist as rings rather than as one large moon.
-
Science & Discovery
Every atom heavier than hydrogen was forged inside a star. Here is how that happened.
Stellar nucleosynthesis is the process by which stars manufacture every element from helium to iron in their cores, and supernovae and neutron star mergers produce everything heavier. The atoms in your body have a detailed provenance that astrophysicists have largely worked out.
-
Science & Discovery
In the first fraction of a second after the Big Bang, the universe grew by a factor of 10 to the 26th power. Here's what we know about that.
Cosmic inflation — a period of exponential expansion in the universe's first 10^-32 seconds — was proposed in 1980 to solve three problems with the standard Big Bang model. Evidence for it is strong; direct detection of its signature in gravitational waves remains the goal.
-
Science & Discovery
Frank Drake wrote seven terms on a blackboard in 1961. Here's what we know about each of them now.
The Drake Equation estimates the number of communicating civilizations in the galaxy from seven factors. In 1961, most were guesses. In 2026, exoplanet surveys, astrobiology, and SETI experiments have turned several of them into data. The answer is still unknown — but for different reasons than before.
-
Science & Discovery
Solar panels stop working past Jupiter. Nuclear reactors are the only practical power source for deep space.
Radioisotope thermoelectric generators have powered deep-space probes since the 1960s. A new generation of compact fission reactors — Kilopower and its successors — could power permanent lunar bases, Mars surface missions, and spacecraft to the outer planets and beyond.
-
Science & Discovery
JWST can sniff exoplanet atmospheres. Scientists are debating what a 'biosignature' actually proves.
Biosignatures — atmospheric chemicals whose presence is difficult to explain without biology — are the primary observational strategy for detecting life on exoplanets. JWST has made the first detections of molecules in rocky exoplanet atmospheres. The challenge is interpreting them unambiguously.
-
Science & Discovery
The Sun occasionally fires plasma clouds at Earth that can knock out power grids. We're not prepared.
Coronal mass ejections — billion-ton clouds of magnetized plasma from the Sun — can trigger geomagnetic storms that damage transformers, disable satellites, and disrupt GPS. The 1859 Carrington Event caused telegraph fires; a comparable storm today would have catastrophic infrastructure consequences.
-
Science & Discovery
Something massive might be hiding at the edge of the solar system. Here's the evidence for and against.
A cluster of distant Kuiper Belt objects have orbits that seem to point toward an unseen planet — perhaps 5 to 10 times Earth's mass, orbiting 400 to 800 AU from the Sun. The hypothesis is compelling, the search is active, and the skeptical case is real.
-
Science & Discovery
Where did the Moon come from? Apollo's rocks are still answering that question.
The giant impact hypothesis — a Mars-sized body struck the early Earth and the debris coalesced into the Moon — has dominated lunar science for 40 years. New analyses of Apollo samples and Chinese lunar returns are both confirming and complicating it.
-
Science & Discovery
For 30 years, the Sun appeared to be broken. Then we realized the problem was the neutrino.
Ray Davis built a detector in a gold mine and counted solar neutrinos for decades — finding only a third of what theory predicted. The discrepancy that resulted forced physicists to rewrite the Standard Model and earned two Nobel Prizes.
-
Science & Discovery
Fast radio bursts are the most energetic millisecond events in the universe — and we're finally finding their sources
For two decades, fast radio bursts were detected but unexplained — extragalactic flashes of radio energy that lasted a millisecond and were gone. CHIME changed the scale of the problem. A magnetar flare in 2020 finally pointed toward an answer.
