<p>Titan appears to be strung like a bead on Saturn’s rings, which cast shadows onto the southern hemisphere of the gas giant in this beautiful image from Cassini.</p> <p style="text-align:center" class="small"><br
<p>Black holes in the early universe needed a few snacks rather than one giant meal to fuel their quasars and help them grow, according to observations from NASA’s Spitzer and
<p>ESA assembled a top engineering team then challenged them to devise a way for rovers to navigate on alien planets. Six months later, a fully autonomous vehicle was charting its