For thousands of years, astronomy has been trying to answer questions in the sky and solve the riddles of the universe. But with every mystery solved, new ones emerge. Astronomers today think they have a pretty good understanding of the workings of our universe. The life cycle of stars, the evolution of galaxies is true that we will have much more information about the process, such as before a century. But there are still many unanswered questions and new ones continue to emerge.
Some of the mysteries of this universe seem to break the accepted rules of the universe. But whether they are, we don’t know until the mystery is solved. Although it takes some time to reach a solution, most of the time we can achieve this. For example, when the ” star that shouldn’t be ” or the rectangular galaxy LEDA 074886, named SDSS J102915+172927, was discovered, scientists joined forces to try to learn more about these celestial bodies with various observation techniques and to understand why they didn’t fit the traditional patterns.
Some mysteries require more patience. For example, if new photos of Miranda, the moon of Uranus, were taken, we could learn more about its turbulent past, but unfortunately, no probe will be sent to Uranus anytime soon.
We will also have to wait for new techniques and new spacecraft to be developed to unravel the mysteries of the Sun’s corona. The “dark matter” that permeates the entire cosmos is still frustratingly obscure.
Perhaps the most exciting mysteries are those that arise unexpectedly, such as dark energy accelerating the expansion of the universe. Thirty years ago, astronomers didn’t even know about such a puzzle, but now dark energy is one of the hottest topics in the field. Discoveries like these help us better understand not only space but also our place in it.
1. Most of the universe is lost
Astronomers face a mystery that undermines much of what we think we know about the universe. We once thought that two substances dominated the universe: normal matter called ” baryonic matter ”
But in the late 1990s, cosmologists discovered something unexpected. The expansion of the universe was supposed to slow down due to the gravitational pull of the materials in the universe, whereas the expansion was accelerating. Evidence for this comes from supernova explosions in galaxies billions of light-years from Earth. Judging by previous cosmic expansion patterns, these explosions are fainter than expected.
The one responsible for this is called ” dark energy ” and it is thought that 70% of the universe is made up of dark energy. We don’t know exactly what dark energy is, but perhaps the most intriguing and even worrying aspect of the discovery is that dark energy seems to be increasing. Up until 7.5 billion years ago, expansion was slowing down. Then the force of dark energy overcame the gravitational pull and the expansion started again.
Some scientists suggest that if dark energy continues to grow, billions of years later it will become so powerful that it will shatter galaxies, stars, and even particles of matter. In this case, our universe may end with the ” Great Rupture “.
2. Impossible stars
In 2011, scientists at the European Southern Observatory discovered a strange star: SDSS J102915+172927, located 4,500 light-years from Earth in the constellation Leo. Named the Caffau Star, the mass of this star is about four-fifths the mass of the Sun. Almost all of its mass is made up of hydrogen and helium, the two lightest elements in the universe. These two elements make up 99.99993% of the star’s composition. Heavier elements (metals) are almost nonexistent.
Such pure and light a star, the longer the 13 billion years ago, the Big Bang that Big Bang ‘from the rest must be made up of raw cosmic material. The problem is that according to accepted models of star formation, this star should never have formed.
For protostar clouds to create enough gravity to collapse and form stars, they must either contain more metal than Caffau’s Star or have a greater mass than it. So small, low-density stars like this shouldn’t exist.
3. Miranda’s secret
Passing by the planet Uranus in 1986, Voyager 2 took pictures of the planet’s moon Miranda. Given the variety of surface features on this small moon, Miranda breaks the rule that small objects show no geological activity. Astronomers have nicknamed the moon the “Frankenstein moon,” which appears to have been torn apart and reassembled, perhaps by an ancient planetary collision.
However, there is a problem with this theory. Miranda is orbiting so close to Uranus that if it had been completely disintegrated, it would never have come together again. That’s why some scientists think Miranda was shaped by being pulled by enormous tides.
4. Rectangular galaxies
According to the laws of orbital mechanics, stars always draw elliptical orbits under the influence of gravity. Therefore, when they come together in large groups, they form either flat disc-like spirals or ball-shaped ellipticals. It must be impossible for galaxies to have sharp rectangular corners, but still, astronomers have found several such rectangular galaxies.
For example, LEDA 074886 in the constellation Eridanus is a small, rectangular galaxy embedded in a nearby galaxy cluster. The real question is whether this shape is a long-lasting structure or a temporary coincidence. Examining it with the giant Japanese Subaru telescope, astronomers think the latter option is more likely, where the collision and merger between the two galaxies might have scattered stars, creating the current box-like array and triggering a wave of star formation at the new center.
5. Orphan planet
By the standard definition, a planet is a celestial body of significant mass orbiting a star, consisting of debris from the birth of a star. So how come some planets are wandering alone in space, far from the stars?
Astronomers have discovered several such planets. The closest and most interesting is the catalog name CFBDSIR J214947.2 040308.9.
First spotted in 2012, this orphaned planet is about 100 light-years away in the vibrant AB Doradus group (a cluster of young stars). A gas giant, probably much heavier than Jupiter, with a surface temperature of around 400 degrees Celsius. It’s still hot, either due to events in its formation or perhaps due to its internal energy source driven by gravitational contraction. Far from the stars to reflect the light of any star. We were able to detect it thanks to the infrared radiation on its surface.
Like all orphan planets, astronomers aren’t sure how they formed. Maybe it started life orbiting one star, then got too close to another star and was thrown away. Or, if formed from the same nebula as the surrounding star cluster, it may not be a planet but a “brown six dwarf star”.
6. The search for dark matter
Since the 1930s, astronomers have been aware that there is much more to the universe than we can see. Normal (baryonic) matter interacts with light and other forms of electromagnetic radiation. Stars emit visible light, hot gases emit X-rays, and even the coldest matter in the universe emits radio waves and infrared light. Clouds made of this type of matter also absorb radiation passing through them.
But another class of matter completely ignores light. This matter, called ” dark matter, ” is completely transparent to all forms of radiation. It only betrays itself by its gravitational effect on visible objects around it (eg, by influencing the orbits of stars in galaxies and galaxies within galaxy clusters).
More recently, astronomers have developed techniques that allow mapping the distribution of dark matter through ‘ gravitational lensing’ (a method of bending light waves passing near large concentrations of matter).
The findings show that dark matter is six times larger than visible matter. But what is the content of this substance? ” Massive compact halo object ” (which can not be detected until the dark and normal matter in uninspiring form, eg. Orphan planets and black holes) was supposed to enlighten this issue, but our telescopes evolved was understood to be available in sufficient quantities of these objects.
7. The corona of the Sun should not be hotter than its surface
The Sun’s visible surface is one of the Sun’s coldest regions. Its average temperature is 5,500 degrees Celsius. However, as you descend towards the core, the temperature rises to 15 million degrees.
We can only see the thin outer atmosphere of the Sun, called the “corona”, from Earth during a solar eclipse. Surprisingly, this corona can quickly rise to 2 million degrees. This massive temperature rise is taking place in a 100-kilometer-thick “transition zone”, and solar physicists still don’t know what triggers it.
Imaging technologies at NASA’s Solar Dynamics Observatory are helping to map both phenomena in detail. In this way, he may soon solve this conundrum. The Parker Solar Probe, launched in 2018, will also attempt to study the corona.
8. Unpredictable pulsars
These collapsed neutron stars (dense cores of massive stars that went supernova long ago) direct intense beams of radiation into space through their strong magnetic fields. Thus, they create a ” cosmic lighthouse ” that, when viewed from Earth, appears to flash many times per second.
Most pulsars emit either X-rays or radio waves (or both), but a unique pulsar, PSR B0943+10, was discovered in early 2013. This pulsar emits alternating radio and X-ray wavelengths and can switch from one type to another within seconds.
According to astronomers, a stellar earthquake can cause such changes as the pulsar’s period changes velocity. But perhaps something more strange and unknown is going on.
9. Galactic balloons
There are two extremely hot gas bubbles stretching 50,000 light-years above and below the Milky Way. ” Fermi bubbles “, discovered with the Fermi Gamma-ray Space Telescope in 2010, are among the largest structures in the universe around us.
10. Origin of cosmic rays
Cosmic rays, high speed, and high energy particles from outer space. We usually detect them through the lower-energy particles they produce when they enter Earth’s upper atmosphere.
So what if GIPs aren’t the source of the highest energy beams? Astronomers are considering the idea that these rays are created by natural particle accelerators around supermassive black holes in distant galaxies.
If high-energy cosmic rays don’t create exploding stars and colliding black holes, astronomers need to come up with something much more powerful.