NASA’s Cassini spacecraft has now officially entered the last phase of its mission – the “Grand Finale,” with the last-ever close flyby of Titan and the first of 22 final orbits which will take the spacecraft closer to Saturn than ever before, passing between the inner rings and the planet itself. Cassini has today just completed the first of these passes (with results pending for a few hours as of this writing), which will culminate on Sept. 15 with the spacecraft plunging into Saturn’s atmosphere to meet its fiery end. It will be a sad but incredible ending to an incredible mission.
For about the past 30 months, the Opportunity rover has been exploring Cape Tribulation on Mars, a towering ridge on the rim of Endeavour crater. Now, Opportunity has finally left that location, to continue its journey southward down the western side of the crater rim. The views have been scenic from the top of Cape Tribulation, but now it is time to move on, and head to the next major target, an ancient gully not too far to the south-east, also on the crater rim. This gully is thought to have been carved by running water millions or billions of years ago, so scientists are very interested in examining it up close, and the rover is now almost there.
This week marks another important milestone in the Cassini mission at Saturn – as of today, the spacecraft is conducting the last Ring-Grazing Orbit of its mission as it prepares for the Grand Finale, which will culminate in the death of the probe on Sept. 15. On April 21, Cassini will do its very last close flyby of Saturn’s largest moon Titan. Speaking of Titan, Cassini has also apparently solved a perplexing mystery; the unusual “magic island” formations seen in one of the moon’s methane/ethane seas are now thought to be caused by nitrogen bubbles fizzing periodically on the sea’s surface.
NASA’s Cassini mission to Saturn has been one of the most successful and awe-inspiring ever, studying the giant ringed planet and its many moons since 2004. But now, scientists are preparing for what everyone knew would come eventually – the end of Cassini’s excursions throughout the Saturn system. Yesterday, NASA held a news conference to celebrate what Cassini has accomplished and outline what will happen during the next few months, culminating with the end of the mission in September.
It may not seem like it, but it is approaching two years now since New Horizons made its historic flyby of Pluto and its moons in July 2015. But even though it has been quiet since then, the mission continues, as the spacecraft is now preparing for its next flyby of another Kuiper Belt Object (KBO) on Jan. 1, 2019 – and now New Horizons has reached the halfway point between Pluto and the next target, called 2014 MU69. It’s another major milestone for a mission that gave us our first close-up views of the Pluto system, and revealed worlds utterly alien and unique in the Solar System.