explainer Astronomy
How hot is the Sun? Surface, core and corona temperatures
How hot is the Sun? The surface is 5,772 K (5,499 °C, 9,930 °F), the core about 15.7 million K and the corona 1 to 2 million K. See how scientists know.
Latest from SciQuestEvidence-led science
explainer Physics
How far away is lightning? The flash-to-bang rule explained
Count seconds from flash to thunder and divide by 3 for km (5 for miles). Why it works, a worked example, and why any…
explainer Earth
How deep is the ocean? Average depth, deepest point and each ocean
How deep is the ocean? About 3,682 m (12,080 ft, 2.3 mi) on average and 10,935 m (6.8 mi) at the Challenger Deep. Depth…
Primary sourcesResearch and official data linked in context
Evidence calibratedObservation, interpretation and speculation separated
Corrections welcomeTransparent updates and a direct reporting channel
Discover
Explore by field and evidence
Choose the kind of evidence you want to read. Labels describe the study type, not whether a finding is true.
Space
Planets, moons, stars and black holes, with the mission data behind each number.
explainer Physics
Gravity on Europa: how strong is it compared with Earth?
explainer Physics
Gravity on Uranus: how strong is it compared with Earth?
explainer Space
How far can the human eye see? From the horizon to 2.5 million light-years
explainer Physics
Gravity on Neptune: how strong is it compared with Earth?
news Astronomy Evidence status: Peer reviewed · Calculated colours from existing spectra and models
White dwarf colours: most look white, a few would glow green or pink
explainer Astronomy
How many moons does Venus have? Zero, and Mercury has none either
explainer Space
Gravity on Venus: how strong is it compared with Earth?
explainer Astronomy
How long does it take to get to each planet? Real mission times
No stories of this evidence type in this field yet.
Physics
Gravity, quantum behaviour and fundamental forces, with the calculations shown.
explainer Physics
How far away is lightning? The flash-to-bang rule explained
explainer Earth
Speed of sound in mph, m/s and km/h: about 343 m/s in 20 °C air
explainer Physics
Gravity on Europa: how strong is it compared with Earth?
explainer Earth
How hot is lightning? About 30,000 K, five times the Sun’s surface
explainer Physics
Gravity on Uranus: how strong is it compared with Earth?
explainer Space
How far can the human eye see? From the horizon to 2.5 million light-years
explainer Physics
Gravity on Neptune: how strong is it compared with Earth?
explainer Physics
How hot is fire? Flame temperatures by colour, fuel and type
No stories of this evidence type in this field yet.
Biology
Genes, evolution and living systems, with study design and sample sizes made clear.
news Biology Evidence status: Peer reviewed · Meta-analysis of published fossil records
Fossil pollen ties plant life’s two biggest turnovers to extreme ancient warmth
news Biology Evidence status: Peer reviewed · Single fossil specimen
Jurassic swimming mammal relative hints suckling anatomy evolved early
news Biology Evidence status: Peer reviewed · Genomics study (embryos and tissues)
Octopus and squid DNA forms flexible loops linked to brain development
news Biology Evidence status: Peer reviewed; observational study of pet dogs
Why big dogs die younger: DNA study finds faster epigenetic ageing
news Biology Evidence status: Mouse study · Peer reviewed
Hidden drainage route found at the back of the eye in mice, but its glaucoma link is untested
News Biology Evidence status: Peer reviewed · Genome-wide association study
What Shapes Personality? Study Finds 1,260 DNA Variants—but Genes Aren’t Destiny
News Biology Evidence status: Peer reviewed · Mouse study
Can Ozempic Slow Aging? Semaglutide Extended Lifespan in Older Female Mice
News Biology Evidence status: Peer reviewed · Human genetic association study
Scientists Identify 36 Risk Genes Linked to OCD and Tic Disorders
No stories of this evidence type in this field yet.
Health
Medical research read carefully: mouse, cell and human evidence kept distinct.
news Biology Evidence status: Mouse study · Peer reviewed
Hidden drainage route found at the back of the eye in mice, but its glaucoma link is untested
News Biology Evidence status: Peer reviewed · Mouse study
Can Ozempic Slow Aging? Semaglutide Extended Lifespan in Older Female Mice
News Biology Evidence status: Peer reviewed · Human genetic association study
Scientists Identify 36 Risk Genes Linked to OCD and Tic Disorders
News AI Evidence status: Peer reviewed · Cross-sectional study
AI Emotional Support Is Linked to Distress in Young People
News Biology Evidence status: Peer reviewed · Laboratory and genomic study
Tuberculosis May Evolve Drug Resistance While Drying in Air
News Biology Evidence status: Peer reviewed · Cell and tissue imaging study
Self-Blinking Probes Image DNA Near Double-Helix Resolution
News Biology
Doctors Injected Mitochondria From a Woman’s Leg Into Her Eyes
News Biology
Two Injections Improved Memory in Alzheimer’s-Model Mice—Not Humans
No stories of this evidence type in this field yet.
Earth
Climate, geology and oceans, traced back to measurements and official records.
explainer Physics
How far away is lightning? The flash-to-bang rule explained
explainer Earth
How deep is the ocean? Average depth, deepest point and each ocean
explainer Earth
Speed of sound in mph, m/s and km/h: about 343 m/s in 20 °C air
explainer Earth
How hot is lightning? About 30,000 K, five times the Sun’s surface
explainer Earth
Why is the sky orange? Red, yellow and pink skies explained
news Earth Evidence status: Peer reviewed · Mineral-proxy study
Crystals hint Earth’s mantle was oxidizing before the Great Oxidation Event
news Biology Evidence status: Peer reviewed · Meta-analysis of published fossil records
Fossil pollen ties plant life’s two biggest turnovers to extreme ancient warmth
news Earth Evidence status: Peer reviewed · Modelling study
Great Unconformity: a vanished cliff may explain the Grand Canyon’s missing billion years
No stories of this evidence type in this field yet.
Selected reading
More from SciQuest
Clear explanations of what scientists found, how they know and what remains uncertain.
explainer Earth
Speed of sound in mph, m/s and km/h: about 343 m/s in 20 °C air
Sound travels about 343 m/s (768 mph, 1,236 km/h) in 20 °C air. See the formula, a temperature table, water and steel speeds, altitude and Mach…
explainer Physics
Gravity on Europa: how strong is it compared with Earth?
Gravity on Europa is 1.31 m/s², about 13% of Earth's and 81% of the Moon's. See NASA data, the GM/R² maths, what you'd weigh and why…
explainer Earth
How hot is lightning? About 30,000 K, five times the Sun’s surface
Lightning's channel peaks near 30,000 K (29,727 °C, 53,540 °F), about five times the Sun's surface. See the sources, the unit mix-ups and why it makes…
How SciQuest reports
Interesting science is stronger when readers can inspect the evidence.
Our editorial standard requires every substantive story to identify what was observed, how it was measured, what researchers infer and what remains uncertain.
Read our editorial standards- 01Find the primary evidence
Start with the paper, dataset, mission record or official technical source.
- 02Test the central claim
Check the method, numbers, scope, uncertainty and alternative explanations.
- 03Explain without inflating
Make the significance clear while preserving limits and scientific context.
Start here
Essential explainers
Durable answers with the numbers, the method and the caveats in one place.
explainer Physics
Gravity on Uranus: how strong is it compared with Earth?
Gravity on Uranus is 8.69 m/s² at the equator, about 0.89 of Earth's, even with 14.5 Earth masses. See NASA's values, the…
explainer Space
How far can the human eye see? From the horizon to 2.5 million light-years
On flat ground the horizon is about 4.7 km away, but on a dark night you can see the Andromeda Galaxy 2.5…
explainer Physics
Gravity on Neptune: how strong is it compared with Earth?
Gravity on Neptune averages 11.27 m/s², about 1.15 times Earth's, despite 17 Earth masses. See NASA values, the maths and what you…
explainer Physics
How hot is fire? Flame temperatures by colour, fuel and type
How hot is fire? Most flames burn at about 900–1,400 °C. See candle, wood fire, gas and Bunsen flame temperatures, and why…