Intellect Plus
Space
396 cards. Each one is a 40-second story with a five-minute read behind it. Page 5 of 7.
- Procyon's hidden companion was predicted 52 years before anyone saw itIn 1844 Friedrich Bessel concluded from Procyon's wobbling motion that an unseen partner must be tugging on it. Not until 1896 did John Martin Schaeberle, peering through Lick Obs…
- Baby stars shine without fusion, powered by gas slamming into themA newborn star is not yet burning hydrogen at its heart. Instead, a protostar glows because gas falling from its surrounding disk crashes into its surface, releasing radiation. Fo…
- The first pulsar was jokingly labelled a signal from little green menIn 1967 graduate student Jocelyn Bell noticed a strange, perfectly regular radio signal ticking every 1.337 seconds. Nothing like it had ever been recorded, and she and her superv…
- The Moon passing in front of 3C 273 cracked the quasar mysteryIn 1962 astronomers timed the Moon's passage across a baffling radio source called 3C 273 to pin down exactly where it sat. That fix let Maarten Schmidt find its faint visible cou…
- The North Star is only 47th brightest, and it keeps misbehavingMany people assume Polaris is the brightest star in the sky. It actually ranks around 47th. Its fame comes from position: it sits less than a degree from the north celestial pole,…
- A green glow in Orion once convinced astronomers they had found a new elementLook at the middle of Orion's sword and one point seems slightly blurred. That smudge is the Orion Nebula, about 1,267 light-years away and the closest region of massive star form…
- The same trick your two eyes use measures the distance to starsGlance at a car's speedometer from the passenger seat and the needle seems to point at a slightly different number than the driver sees. That shift is parallax, the apparent movem…
- Two brightness readings through coloured filters can reveal a star's temperatureMeasure a star through a blue filter, then a yellow-green one, and subtract. That single number, the colour index, tells astronomers how hot the star's surface is. For 51 Pegasi i…
- Einstein tweaked his own equations to stop the universe from movingIn 1917 Einstein added a cosmological constant to general relativity for one reason: to keep the universe static, as he believed it was. Within about a decade a Belgian priest pro…
- The Pinwheel Galaxy is nearly three times as wide as the Milky WaySeen face-on from 21 million light-years away, Messier 101 spans roughly 252,000 light-years and holds around a trillion stars. Its arms are lopsided because neighbouring galaxies…
- The ancient Greeks counted the Sun and Moon as planets, but not EarthPlanet means wanderer. To ancient observers it meant the Sun, the Moon and five bright points drifting against the stars; Earth joined the club only when heliocentrism won out. Si…
- Planetary nebulae have nothing to do with planets, and the Sun will make oneThrough early telescopes, these glowing rings looked like faint planetary disks, so the name stuck. They are actually the shed outer layers of dying stars, lit up by the exposed c…
- Our tidy arrangement of planets looks unusual among thousands of known systemsSmall rocky worlds close to the Sun, giant planets farther out: it feels like the natural order. Yet among 4,809 planetary systems confirmed by April 2026, few resemble ours. More…
- Why the Seven Sisters so often show only six starsAcross the world, people pictured the Pleiades as seven sisters, and their stories often explain why one went missing. Some scientists suspect the tales reach back to around 100,0…
- Orion the hunter is a signpost to half the winter skyFew star patterns are as easy to spot as Orion, an hourglass of bright stars pinched by a neat row of three. Named for a hunter of Greek myth and catalogued by Ptolemy in the seco…
- Neptune was found with a pen before anyone saw it through a telescopeUranus kept drifting off the path astronomers predicted for it, as if something unseen were tugging it. Two mathematicians worked out where that something should be. On 23 Septemb…
- Why Earth gets more daylight than darkness over a yearIf Earth were an airless world lit by a point of light, day and night would split the year evenly. They don't. The Sun's width and the bending of light by our atmosphere steal sev…
- A nova's new star is actually the burned-out core of a very old oneNova means new star, and to anyone watching, that is how one looks: a point of light where none shone before. The truth is almost the reverse. Nearly every nova erupts on a white …
- Why the visible universe reaches 46.5 billion light-years in every directionLight has been travelling for at most 13.8 billion years, so you might expect the visible universe to end 13.8 billion light-years away. Its edge actually lies about 46.5 billion …
- The best stargazing spot on Earth may be a ridge in AntarcticaAstronomers hunting for perfect skies look for darkness, dryness, height and endless clear nights. A 2009 study concluded that the place offering all of these with the least atmos…
- Omega Centauri may be the leftover heart of a swallowed galaxyFor 1,500 years Omega Centauri was listed as a single star on the Centaur's back. It is actually a ball of roughly 10 million stars, the biggest cluster of its kind in our galaxy,…
- Nobody has seen the Oort cloud, yet its comets keep arrivingNo telescope can image the Oort cloud, a shell of icy bodies that may stretch more than three light-years from the Sun. Jan Oort deduced it in 1950 from a simple puzzle: comets th…
- To catch a spacecraft ahead of you in orbit, don't hit the acceleratorTwo spacecraft share a circular orbit, one trailing the other. The obvious move is for the rear craft to fire its engine and speed forward. Do that, and it climbs to a higher orbi…
- A nebula the size of Earth would weigh only a few kilogramsNebulae look like solid glowing clouds in photographs, yet most are thinner than the best vacuum any laboratory on Earth can make. A patch of nebula as big as our planet would hol…
- The idea that planets grew from a spinning cloud began with a philosopherLong before telescopes could see a single planet around another star, the philosopher Immanuel Kant argued that the Solar System condensed from a slowly turning cloud of gas. His …
- The Moon probably formed when a Mars-sized world struck the young EarthAbout 4.51 billion years ago, the favoured story goes, a body the size of Mars, nicknamed Theia, struck the infant Earth at a glancing angle. Molten debris thrown into orbit gathe…
- Why we stopped calling moons satellites, and what counts as oneKepler coined satellite in 1610, borrowing the Latin satelles, a guard or attendant, for the four companions Galileo had spotted around Jupiter. The word served astronomers for ce…
- The main sequence: the long, steady middle age of nearly every starPlot stars by colour against true brightness and most fall along one diagonal band. That band, the main sequence, is where stars spend the bulk of their lives fusing hydrogen in t…
- Mars may owe its lopsided face to a Pluto-sized collisionThe northern half of Mars is low and smooth, the southern half high and battered by craters. One explanation is a strike by a body the size of Pluto some four billion years ago, w…
- On Mercury, a single sunrise-to-sunrise day lasts two of its yearsMercury spins three times for every two trips around the Sun, a lockstep that stretches one solar day to about 176 Earth days. Any spot on the surface bakes in sunlight for 88 day…
- To an astronomer, oxygen and carbon count as metalsAstronomers lump every element heavier than helium together as metals, even gases like oxygen that chemists would never call metallic. The quirky shorthand hides a useful clock: b…
- The 1833 Leonid storm proved shooting stars come from spaceOn a November night in 1833, meteors fell over eastern North America at an estimated hundred thousand or more an hour. Denison Olmsted noticed they all streamed from one spot in L…
- Meteoroid, meteor, meteorite: one space pebble, three namesRoughly 25 million bits of space rock and dust plunge into Earth's atmosphere every day, adding up to around 15,000 tonnes a year. While drifting through space each is a meteoroid…
- Spilled milk, a silver river, a path of straw: naming our galaxyGreeks saw spilled milk in the pale band across the night sky, giving us both Milky Way and the word galaxy. Across East Asia it is the Silver River. Finns and Lithuanians call it…
- How an asteroid ended up named after a cat called Mr. SpockThe first asteroids took names from Greek and Roman myth. As discoveries piled into the thousands, astronomers turned to spouses, colleagues, fictional characters and even pets. T…
- Stars are born in cold clouds whose main gas is almost invisibleMolecular hydrogen fills the dark clouds where stars form, yet its symmetrical molecules barely emit anything a telescope can catch. Astronomers found the clouds by chasing a stan…
- The biggest stars are not the most luminous onesBetelgeuse is about 1,000 times wider than the Sun and shines around 100,000 times as brightly. Yet R136a1, only 39 times the Sun's width, pours out more than 6.1 million times th…
- A blood moon is lit by a ring of sunsets around the EarthDuring a total lunar eclipse, anyone standing on the Moon would see the Sun hidden behind a dark Earth circled by a thin red ring. That ring is our atmosphere, bending sunlight in…
- Star magnitudes run backwards because they began as a ranking of sizeIn astronomy, smaller numbers mean brighter stars, and the brightest go negative: Sirius sits at minus 1.46, the Sun at minus 27. The oddity dates back two thousand years, to when…
- Shapeless galaxies may be the closest living relatives of the universe's first onesAbout a quarter of all galaxies fit neither the spiral nor the elliptical mould. These irregulars have no central bulge, no arms and no symmetry. The smallest of them, dwarf irreg…
- Why the stretch from March to September lasts a week longerFrom the March equinox to the September one takes about 186 days; the return trip takes only about 179. The gap exists because Earth's orbit is a slightly squashed ellipse and our…
- The Kuiper belt is named after an astronomer who thought it had vanishedGerard Kuiper did sketch a disc of icy bodies beyond Neptune, but he assumed Pluto was massive enough to have flung them all away. Had he been right, no belt would exist today. It…
- Jupiter drags two rival camps of asteroids named for the Trojan WarSixty degrees ahead of Jupiter and sixty degrees behind it, two gravitational sweet spots hold more than a million asteroids. Astronomers named those ahead after Greek heroes of t…
- Magellan got the credit, but Vespucci wrote about this galaxy firstIn a letter from 1502, Amerigo Vespucci described three Canopi in the southern sky, two bright and one dark. The bright pair were the Magellanic Clouds, satellite galaxies of the …
- Lenticular galaxies look like spirals that have run out of fuelPicture a spiral galaxy with its arms erased and its star-making gas gone. What remains is a lenticular galaxy: a smooth disc around a fat central bulge, filled with stars all tho…
- Our galactic neighbourhood is a dumbbell whose two ends are falling togetherThe Milky Way belongs to a family of galaxies shaped like a dumbbell. We and our satellites form one lobe; the Andromeda Galaxy and its companions form the other, roughly three mi…
- Astronauts in low orbit float despite feeling almost full Earth gravityUp where the space station flies, gravity is only slightly weaker than on the ground, because a few hundred kilometres is tiny compared with Earth's radius. Astronauts float becau…
- The bull's face in Taurus is a star family slowly drifting apartThe V of stars forming the face of Taurus looks like one group, but its brightest point, orange Aldebaran, is an impostor only 65 light-years away. The rest belong to the Hyades, …
- In 2022 humans nudged an asteroid, and beat the target by a mileOn 26 September 2022 NASA deliberately crashed a spacecraft into a small asteroid to see whether it could shift its path. Mission planners would have counted a change of 73 second…
- Is space between the planets hot or cold? Two rivals were both rightJoseph Fourier guessed that the space between planets was about as cold as Earth's poles. In 1959 Sydney Chapman argued it was blisteringly hot, around 10,000 degrees. The gas out…
- The space between stars is emptier than any lab vacuum, yet behaves like weatherOn 25 August 2012 Voyager 1 became the first human-made object to reach interstellar space. What it entered is thinner than the best vacuum chambers on Earth, sometimes just 100 i…
- A navigation engineer spotted the first volcano erupting beyond EarthShortly after Voyager 1 swept past Jupiter's moon Io in March 1979, navigation engineer Linda Morabito noticed an odd plume rising from its edge in one image. Other pictures soon …
- Something hidden behind the Milky Way is tugging on our galaxyOur galaxy and thousands of its neighbours are drifting towards a patch of sky we can barely see, blocked by the dust and stars of the Milky Way. Astronomers named the target the …
- The element that never was: how glowing star nurseries fooled astronomersNineteenth-century spectroscopes revealed a bright green line at 500.7 nanometres in some nebulae that matched no known element. Astronomers called the mystery substance nebulium.…
- A simple star chart once sparked a feud over the age of EarthPlot stars by brightness against temperature and they fall into tidy bands instead of a random scatter. Early astronomers read that pattern as stars shrinking over time, powered b…
- Standing on a beach, the horizon is only about five kilometres awayThat distant line where sea meets sky feels infinitely far, yet for someone of average height standing at the water's edge it lies just under 5 kilometres off. Climb Mount Everest…
- Orion's famous horse's head is a silhouette of dust, found on a photographNobody first spotted the Horsehead Nebula through an eyepiece. In 1888 the Scottish astronomer Williamina Fleming noticed it on a photographic plate at Harvard College Observatory…
- Hubble's law was found first by a Belgian priest who edited himself outTwo years before Edwin Hubble's famous 1929 paper, Georges Lemaître, a Belgian priest and astronomer, showed that distant galaxies recede at speeds proportional to their distance.…
- Why satellite dishes can point at one fixed spot in the skyAt 35,786 kilometres above the equator, a satellite takes exactly as long to circle Earth as the planet takes to turn, so from the ground it seems to hang still. A science fiction…
- Some synchronised satellites trace a figure eight across the sky each dayA geosynchronous satellite circles Earth once every 23 hours, 56 minutes and 4 seconds, matching the planet's spin. Only a perfectly circular one over the equator stays fixed over…