Stellar parallax: how geometry reveals the distance to stars
Learn how Earth’s orbit makes stellar parallax measurements possible, how to calculate distances in parsecs, and how to interpret telescope uncertainties.
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Astronomy in Layers
Astronomy explained step by step to understand planets, stars, galaxies, black holes, cosmology, and how science investigates the Universe.
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Black Eye Galaxy with Webb: what infrared reveals in M64
The Hubble and Webb comparison shows how dust, stars, and star-forming regions change appearance depending on the wavelength being observed.
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Curiosity reaches 5,000 sols: the discoveries that still guide the Mars mission
Sol 5,000 condenses 14 years of Mars science. See how water, habitability, clays, organics, wet-dry cycles, and recent finds changed Curiosity's scientific questions.
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McGetchin crater on the Moon: how LRO dated the impact and why it is rare
LRO constrained the formation of McGetchin crater to a few weeks in 2024. See how the image comparison worked, what was measured, and what remains an estimate.
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Solar System2 articles
Planets, moons, asteroids, comets and the processes that formed and continue to transform our cosmic neighborhood.
Stars & Extreme Objects2 articlesThe formation, evolution and death of stars, including supernovae, neutron stars and black holes.
Galaxies & Nebulae1 articleThe Milky Way, nebulae, galaxy types and the large structures formed by stars, gas and dust.
Cosmology1 articleThe origin, evolution and structure of the Universe, from the Big Bang to cosmic expansion, dark matter and dark energy.
Exoplanets & Life4 articlesWorlds beyond the Solar System, detection methods, habitability, atmospheres and the scientific search for life.
Methods, Telescopes & Missions5 articlesHow observatories, instruments, light and missions make it possible to discover and measure objects in the Universe.
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Elias 2-24 b: how the youngest known planet was confirmed and why it shortens the formation timeline
Elias 2-24 b belongs to a system younger than 1 million years. See how Keck, ALMA, and VLT confirmed the planet and which conclusions about age, mass, and formation still depend on...
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Webb found two-Jupiter-mass brown dwarfs: why they challenge star-formation models
In IC 348, Webb confirmed brown dwarfs with estimated masses of about twice Jupiter's. Here is why that strains fragmentation models, what the spectra show, and what the finding st...
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Can the Universe expand faster than light? What relativity actually limits
Yes. Cosmological distances can grow faster than light without matter or information locally exceeding c. Here is how inflation, recession, and horizons fit together.
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Does radial velocity measure an exoplanet's true mass? Understanding M sin i
Radial velocity usually yields M sin i, the minimum mass. Learn how inclination changes the true mass and how transits or astrometry break the degeneracy.
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Parker Solar Probe’s 29th perihelion: why it spent nine days out of contact and what its camera targeted near the Sun’s north pole
The communications gap was planned and the spacecraft operated autonomously. Here is the timeline of the 29th perihelion, WISPR’s role, and what still depends on data returned to E...
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Asteroid 2026 RW1: how ESA estimated entry and the strewn field without direct footage
See how astrometry, orbit determination, atmospheric modelling and Monte Carlo turned a few hours of observations into an entry and possible strewn-field forecast.
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MOONS on the VLT: how 1,000 fibres observe a thousand stars and galaxies at once — and what first light really tests
MOONS uses roughly 1,000 robotic fibres to obtain hundreds of spectra in parallel on the VLT. Learn how light travels through the instrument, how an image differs from a spectrum, ...
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Hubble + Webb on trans-Neptunian objects: how colors and orbits preserve clues to Solar System formation
Hubble and Webb combined visible and infrared light to study tiny TNOs and test what their colors, orbits, and sizes preserve about their origins.
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Little red dots: what Webb’s 40+ lines really support about “black hole stars”
GLIMPSE-17775’s spectrum combines electron scattering, H/O/He lines, an iron “forest,” and high-energy diagnostics consistent with the BH* scenario — without settling the question.
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- 01Is the CD-35 2722 B exosatellite the first exomoon? What the study actually detectedExoplanets & Life
- 02Hubble + Webb on trans-Neptunian objects: how colors and orbits preserve clues to Solar System formationSolar System
- 03Asteroid 2026 RW1: how ESA estimated entry and the strewn field without direct footageMethods, Telescopes & Missions
- 04Parker Solar Probe’s 29th perihelion: why it spent nine days out of contact and what its camera targeted near the Sun’s north poleMethods, Telescopes & Missions
- 05MOONS on the VLT: how 1,000 fibres observe a thousand stars and galaxies at once — and what first light really testsMethods, Telescopes & Missions
Solar System
Planets, moons, asteroids, comets and the processes that formed and continue to transform our cosmic neighborhood.
McGetchin crater on the Moon: how LRO dated the impact and why it is rare
LRO constrained the formation of McGetchin crater to a few weeks in 2024. See how the image comparison worked, what was measured, and what remains an estimate.
Read articleHubble + Webb on trans-Neptunian objects: how colors and orbits preserve clues to Solar System formation
Hubble and Webb combined visible and infrared light to study tiny TNOs and test what their colors, orbits, and sizes preserve about their origins.
Read articleStars & Extreme Objects
The formation, evolution and death of stars, including supernovae, neutron stars and black holes.
Webb found two-Jupiter-mass brown dwarfs: why they challenge star-formation models
In IC 348, Webb confirmed brown dwarfs with estimated masses of about twice Jupiter's. Here is why that strains fragmentation models, what the spectra show, and what the finding st...
Read articleLittle red dots: what Webb’s 40+ lines really support about “black hole stars”
GLIMPSE-17775’s spectrum combines electron scattering, H/O/He lines, an iron “forest,” and high-energy diagnostics consistent with the BH* scenario — without settling the question.
Read articleGalaxies & Nebulae
The Milky Way, nebulae, galaxy types and the large structures formed by stars, gas and dust.
Black Eye Galaxy with Webb: what infrared reveals in M64
The Hubble and Webb comparison shows how dust, stars, and star-forming regions change appearance depending on the wavelength being observed.
Read articleNo articles published yet.
Cosmology
The origin, evolution and structure of the Universe, from the Big Bang to cosmic expansion, dark matter and dark energy.
Can the Universe expand faster than light? What relativity actually limits
Yes. Cosmological distances can grow faster than light without matter or information locally exceeding c. Here is how inflation, recession, and horizons fit together.
Read articleNo articles published yet.
Astronomy without skipping steps
Astronomy in Layers was created to make astronomy understandable without turning science into misleading simplifications. The blog moves through planets, stars, galaxies, black holes, exoplanets, and the evolution of the Universe itself, building each explanation on concepts introduced earlier.
In addition to answering what each object or phenomenon is, we seek to explain how it works, how astronomers reached current conclusions, and which questions remain open. Whenever a topic depends on models, estimates, or scientific hypotheses, that distinction should be made clear in the text.
The goal is for a reader to begin with little prior knowledge and, article by article, build an increasingly complete understanding of the Universe.