In this week's Science Saturday, from sleep quality to the first-ever all-civilian mission to space, let's take a look at what's making news in the world of science. 

1. Sleep patterns

A full moon can affect human sleep cycles. Researchers from the University of Washington say sleep patterns among the study's 98 participants appeared to fluctuate over the course of the 29-and-a-half-day lunar cycle. So they found - three to five days before the moon reaches its brightest phase, people go to sleep later in the evening and sleep for shorter periods of time. One theory has been linked to the changing availability of moonlight as the lunar cycle progresses. 

2. Ancient tree

Greek scientists have found a rare, fossilized tree, whose branches and roots are still intact after 20 million years. The rare finding was made near an ancient forest, petrified millions of years ago on the volcanic island of Lesbos. The tree is about 19 meters long, and was preserved by a thick layer of volcanic ash after it fell. It's by far the most well-preserved fossilized tree found in the region since excavations began in 1995.  

3. Space mission 

Space X is launching the world's first all-civilian mission to space this year. The multi-billion orbital flight is funded by entrepreneur Jared Isaacman, who will also command the trip. It's not exactly clear how long the trip will be or where in orbit it will fly. Isaacman has purchased three additional seats aboard the mission. All four civilian astronauts, including Isaacman, will undergo training before they blast off, which is slated for the fourth quarter of this year.  

4. Space exploration

The world's first commercial biofuel rocket has successfully taken off. BlueShift Aerospace, a space start-up, launched its Stardust 1.0 rocket prototype from Maine, the United States, on Sunday. Stardust 1.0 is a small sounding rocket powered by a "bio-derived" solid fuel. It stands 6 meters and can carry 8 kilograms of payload. The mission is a major milestone for the company aiming to launch bespoke missions tailored for tiny satellites. 

"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.