This week in science is a review of the most interesting scientific news of the past week.
Existence of orbiting supermassive black holes confirmed
Astronomers from the University of New Mexico have observed and measured for the first time ever the orbital motion between two supermassive black holes. To collect the data, the scientists have used the Very Long Baseline Array (VLBA), which is a system of 10 radio telescopes across the US.
Because of the black holes’ combined mass of about 15 billion solar masses, the orbital period is around 24,000 years, which explains why it took 12 years of observations for scientists to conclude they are orbiting each other. According to Professor Greg Taylor from the University of New Mexico:
"For a long time, we've been looking into space to try and find a pair of these supermassive black holes orbiting as a result of two galaxies merging. Even though we've theorized that this should be happening, nobody had ever seen it until now."
The massive black holes are roughly 750 million light-years from Earth in a galaxy named 0402+379 and this discovery may help astronomers understand the future of our own galaxy, the Milky Way. That is because the Andromeda galaxy is on a path to collide with it in a few billion years – nothing you should be afraid of.
Finally, to confirm the motion and to obtain the precise orbit between those supermassive black holes, the research team will observe and measure the system in three or four years from now.
The damage caused by the increase of 0.5°C
A new study published on the scientific journal Nature has related the increase of only 0.5°C, or 0.9°F, to the increase of heat waves and heavy rains in many regions of the world. The scientists have compared two 20-year periods, namely 1960-1979 and 1991-2010, analyzing the average global temperatures and extreme weather duration and intensity.
According to the recorded data for those periods across 25 percent of Earth’s land areas, the hottest summers experienced a 1°C, or 1.8°F, increase in temperature while the coldest winters were also 2.5°C, or 4.5°F, hotter. Also, extreme precipitation grew about 10 percent for those areas while hot spells were lengthened by a week across half of Earth’s land areas. As stated by Erich Fischer, from ETH Zurich in Switzerland and co-author of the paper:
"With the warming the world has already experienced, we can see very clearly that a difference of 0.5 C really does matter."
The world is currently experiencing an increase of about 1°C on its average temperature and scientists are now pushing for governments to stick to the 1.5°C, or 2.7°F, increase target. According to the Paris Agreement, the red line for global warming would be an increase of 2°C, or 3.6°F.