In this week's Science Saturday, from an ocean-mapping satellite to new findings in Pompeii, let's take a look at what's making news in the world of science.

Fossil galaxy

First, astronomers found a "fossil galaxy" hiding inside the Milky Way. Called Heracles, the dead galaxy is left over from the early universe. And it's believed to have collided with the Milky Way around 10 billion years ago. Researchers say the remnants account for almost half the mass of the entire Milky Way halo, which is made up of star clusters, gases and dust. They say this new discovery could change humanity's understanding of our universe, as well as the formation of the Milky Way. 

New satellite launch

A satellite, critical to the understanding of climate change, has blasted off from California. Sentinel-6 took off from the Vandenberg base on a SpaceX Falcon-9 rocket. The satellite is roughly the size of a small pickup truck, and was built by Airbus in Germany, at a cost of nearly $100 million. It's the first of a pair of identical ocean-mapping satellites. The other – Sentinel-6B – is expected to launch in 2025. Together, they will carry on NASA's three-decade-long effort to document rising sea levels and will give scientists a more precise view of the coastlines. 

Pompe II remains

The bodies of a rich man and his slave, who lived nearly 2,000 years ago, have been found in the ancient Roman city of Pompeii. They were burnt to death by the volcanic eruption that destroyed the city in 79 A.D. The wealthy man, with traces of a woolen cloak, was between 30 and 40, while his slave, in simple attire, was probably aged 18 to 23. They were believed to be sheltering in a side room along an underground corridor, but failed to escape the volcanic blast. 

Pollution at the world's highest peak

Microplastics have been found on the world's highest peak, Mount Qomolangma. It's believed to be left from the equipment used by the hundreds of climbers who visit the peak every year. The tiny pollutants were found as high as 8,440 meters above sea level. Items carried by trekkers and climbers, like fluorescent tents, discarded climbing equipment and empty gas canisters, are often the cause of plastic pollution, causing a potential threat to the mountains.

"Science Saturday" is part of CGTN's science and technology series "Tech It Out." The segment brings you the latest news about innovations and technological breakthroughs in the past two weeks from across the world.