Space smells like steak, stars sing, and astronauts grow 5 centimeters: little-known facts for Astronomy Day that will surprise you

Every year, humanity stops twice to raise its head up. International Astronomy Day on April 25 is not just a date on the calendar, but an opportunity to remember: the Universe is much stranger than it seems. And while most people think they know everything about space from school lessons, science has long discovered such things that take your breath away.

Ukrainian News Agency has collected the most interesting little-known facts about astronomy - those that are rarely written about in textbooks, but which make you look at the sky above your head in a new way.

A holiday that was born from one simple idea - to take a telescope outside

International Astronomy Day was founded in 1973 by Doug Berger, president of the Northern California Astronomical Association. His idea was simple: to place telescopes in the open sky in different parts of the city so that ordinary passers-by could look at the stars. From that simple idea grew an international movement.

Today, the holiday is celebrated twice a year - in the spring and autumn, each time on a Saturday near the first quarter of the moon. In 2026, Spring Astronomy Day falls on April 25. The slogan of the holiday is "Bringing Astronomy to the People". Thousands of observatories, planetariums and science museums around the world open their doors to all comers on this day.

Space smells - and this smell will surprise you

One of the most amazing facts that few people know: outer space has a smell. After going into outer space, many astronauts have noticed an unusual aroma in their spacesuits - from the smell of metal to overcooked steak on charcoal. The explanation for this is polycyclic aromatic hydrocarbons, which are formed during the death of stars. The same substances are released when burning wood and coal - hence the familiar smell.

And at a distance of 12 billion light years from Earth, astronomers discovered a colossal cloud of water vapor, which contains 140 trillion times more water than in all the Earth's oceans combined. This is a reminder that water is not an exclusively terrestrial phenomenon.

Stars sing, storms rage for 200 years, and rain is made of glass

Stars emit acoustic waves that are recorded in the form of vibrations of their surfaces. The Sun and some other stars literally "sing", making sounds similar to a low-frequency hum. It is impossible to hear this with the ear - but special equipment records these vibrations.

The Great Red Spot on Jupiter is a storm that has been raging there for more than 200 years. For comparison: the longest hurricanes on Earth last several weeks. And on one of the exoplanets, scientists recorded a rain of molten glass - there are no drops there, there are streams of silicate particles moving at a speed of more than a thousand kilometers per hour.

One of the densest known exoplanets - Kepler-10b - is 20 times heavier than the Earth, but only twice as large in diameter. A person weighing 70 kg on its surface would weigh more than 1,400 kg.

Astronauts grow in space, and "shooting stars" are not stars at all

Since in space the human body is not affected by Earth's gravity, astronauts become about 5 centimeters taller during the flight. When they return to Earth, their height returns to the previous one.

What we are used to calling a "shooting star" is actually the remains of a comet or space dust. When they enter the atmosphere, they begin to burn, producing bright light. It has nothing to do with stars.

And the Moon is 400 times smaller than the Sun, but it is also 400 times closer to Earth. That is why they look the same size from our planet - and that is what makes solar eclipses so spectacular.

Black holes glow, but most of the Universe is unknown

A black hole is actually the brightest object in the Universe. Inside it, the gravitational force is so great that not even light can escape. But as it rotates, the hole absorbs gas clouds, which begin to glow brightly.

Stars and planets make up only about 5% of the mass of the Universe - the remaining 95% remains unknown to science. This is the so-called dark matter and dark energy - things that scientists can neither see nor fully explain.

About 40 new stars are born in our galaxy every year. And while we look at the night sky, some of the stars we see have long since disappeared - we observe their light, which has been flying to us for millions of years.

Let us remind you, the "pink Moon" and the powerful Lyrids meteor shower: what Ukrainians will see in the sky in April.