This year, astronomers have made great efforts to observe the universe. Here is a summary of astronomical news from 2018.
It was an exciting year for space missions. One of them started toward the inner solar system to touch the sun, and another left the solar system completely to touch the interstellar space – a whopping 18 billion kilometers from home. Both illuminate extreme and distant environments. Meanwhile, other missions focus on environments that look more like home – working towards a better understanding of the Earth and its planets.
In April, for example, the TESS mission launched to study nearby exoplanets, increasing the odds that astronomers could soon find more habitable homes. At the end of November, NASA's Insight Lander reached Mars on its first mission to investigate the interior of the planet. This is particularly exciting as two findings this year have increased the likelihood that the Red Planet may have once harbored life: the first found organic molecules in ancient rocks and the second discovered an underground salt lake.
While these missions highlight the potential for future discoveries, the year has also brought a series of sad ends. We said goodbye to beloved scientist Stephen Hawking, who helped reveal many of the secrets in the black holes, and the Kepler Space Telescope, which revealed thousands of alien worlds. Yes, it has been a whole year. Below are the top 1
LIGO: The gift that passes on
In December, scientists identified four other ghostly signals from distant black hole pairs that swirled and collided. This increased the total number of gravitational wave detections to 11. The announcement was not only the largest number of detections released at once, but one event was the most distant and powerful black hole fusion yet. It occurred five billion years ago when two large black holes merged into an 80-solar mass giant and released the energy of 5 solar masses in the form of strong gravitational waves.
Voyager 2 leaves the solar system
On Dec. 5, Voyager 2 entered interstellar space – making it the second probe in history to travel so far beyond Voyager 1's homeland. Astronomers did not notice the event at the distance of the probe (a whopping 18 billion kilometers) from home, but due to a decrease in the solar wind. The sun sends out a steady breeze of charged particles far beyond Neptune, but this wind eventually gives way to the interstellar plasma that fills the galaxy. When the plasma detector aboard Voyager 2 detected a significant decrease in solar wind velocity, the mission scientists knew that the probe had officially entered interstellar space. At their current speed, the Voyagers will hit the inner edge of the Oort Cloud in about 300 years – the icy shell of debris surrounding our solar system.
Insight Lander reaches Mars
In late November, NASA's Mars Insight (Interior) reconnaissance with seismic surveys, geodesy and heat transport) landed on the Red Planet. It is NASA's eighth successful landing on Mars and the first dedicated geophysical mission.
Insight will record "Martian earthquakes" and other geological activity to answer some questions about the interior of the planet. For example, scientists want to know how similar the planet is to other rocky worlds. Soon the lander will drill a millimeter into the surface of the planet one millimeter at a time. After 30 or 40 days of drilling, Insight will sit quietly to take targeted seismic measurements and evaluate our neighbor's activity.
Astronomers guess a black spot event
Using the GRAVITY instrument for the Very Large Telescope Interferometer in Chile, astronomers discovered three bright torches near the central supermassive black hole of our galaxy, Sagittarius A *. Each torch lasted between 30 and 90 minutes and raced around the black hole at 30% light speed. The astronomers suspect that the torches were created within the swelling disk that slowly feeds the black hole. This is a realization that enables them to test gravity in one of nature's most extreme environments.
Scientists set foot on an asteroid
In early October, the Mobile Asteroid Surface Scout mission (MASCOT) successfully landed on the tiny 162703 Ryugu asteroid. It was the first mission to explore the surface of an asteroid on the ground and walk over the tiny rock for three days and two nights to better appreciate the beginnings of solar system formation.
However, it was not the only asteroid explorer to be explored this year. One month later, NASA's Osiris-REX spacecraft arrived in Bennu and quickly discovered that water had once soaked the rocks. Osiris-REX will enter orbit around Bennu on December 31 this year. Finally, a sample of material is taken to return to Earth in 2023.
A spacecraft starts to touch the sun
The Parker Solar Probe was launched at the end of the summer From Cape Canaveral, on a mission that will uncover a series of secrets about our beloved host star, bringing an instrument suit closer to the sun than ever before – plunges into the lower solar corona to determine the origin and acceleration of the It will not be easy, the daring spacecraft has to fight against the intense wind and the hot heat of the sun, but if successful, a new window opens up to solar physics.
The Potential for the Life of Mars increases  Two exciting insights this year increased the likelihood that the Red Planet once contained the necessary ingredients for life. Initially, the Curiosity Rover discovered organic molecules in ancient rocks. While these molecules do not have to be produced by life, life produces and uses some of them (such as sugars and amino acids). Then a second instrument discovered evidence of today's liquid water on Mars – or more precisely, a salty underwater lake. Both are promising finds.
Gaia Maps the Milky Way
The Gaia space satellite released its second data stack in late April, containing accurate parallax (and hence distances) for more than 1.3 billion stars and positions and magnitudes of nearly 1.7 billion Stars in total. This second number represents just over 1% of all stars in our galaxy and is a detailed map of our neighborhood.