Launched 15 October 1997, the Cassini Mission is in its 20th year. It reached Saturn and entered orbit on 1 July 2004. Details of the mission can be read at this Wikipedia summary. This post is mostly about the maneuvers by Cassini to change its orbit and make 22 close encounters with Saturn in what is called the Grand Finale. End of mission is scheduled for 15 Sep 2017 when the spacecraft plunges into the atmosphere of Saturn ending a long and brilliant exploration of the famous ringed planet, its rings, and 62 moons.
Astronaut twins Mark and Scott Kelly participated in a study conducted by ten researchers on the effects of long duration space flight. Scott was aboard the International Space Station for 340 days while Mark remained on Earth. Scott returned to Earth 1 March 2016. For details about his return, read this previous post.
Ten researchers reported preliminary results on 23 Jan 2017 in Galveston TX of their comparative studies of the twins. The NASA issued statement is here. I’ll attempt to summarize eight of their findings below.
🔭 Updates an earlier post to include recent changes and information.
As an amateur astronomer, I use desktop planetarium software to plan viewing sessions and keep track of the planets and Moon. There are many products available for all computer platforms and smartphones. A Google search yields links to many sources. I downloaded and use the open source Stellarium on my desktop computer. It can be customized to your location and is free. For Android and Mac phones and tablets, I like SkySafari. It isn’t free.
Online planetarium sites are popular and offer many features. Below are highlights of some I find interesting. Each has multiple features, a unique look and feel, and different levels of detail. They can help satisfy your curiosity about astronomical events.
I limited this post to include only a few select sites and links. Since many are available, it’s easy to be overwhelmed with too much information. I hope these few of top quality will motivate you to investigate the sky and enjoy what it has to offer. I welcome reader questions or reviews about using these tools or others you find helpful.
On 24 January 2004, NASA’s Mars Exploration Rover Opportunity landed and started exploration. It joined the Spirit Rover which landed three weeks earlier on a different part on the Martian surface. The twin rovers were designed for mission lifetimes of 90 days.
Spirit’s last communication with Earth was 22 March 2010 more than six years into the mission. Opportunity is still operating well and continues to return images and data to Earth after thirteen years. It recently completed a marathon of distance travelled. Detailed maps are available here. To celebrate entering teenage, NASA Jet Propulsion Laboratory released this entertaining video about the milestone.
How will the Moon look today, on your birthday, or any date in 2017? Find out at NASA Dial-a-Moon. Enter any month, day, and universal time (UT) hour to see a high definition image. The composite images of Dial-a-Moon are made from those of the Lunar Reconnaissance Orbiter (LRO) in low altitude orbit around the Moon since 2009. Here is the link for southern hemisphere readers.
You may leave the universal time (UT) at the default 1 value. If you are a curious type, Universal time conversion can be done at this link. Enter UTC in the lower right box if it isn’t already set. You can switch from 12 hr to 24 hr at the bottom of the entry boxes. You may also enter any other local time in the upper left box. Go back to Dial-a-Moon to enter the UT.
The collection of accurate images of the Moon for each hour have been made into a movie lasting 5 minutes. Try watching full screen and increase the speed by 2x. Speed can be changed using the gear icon ⚙ after the movie starts. Two versions of the movie are available for readers in northern and southern hemisphere.
I explain the peculiar wobble and tipping motions at this blog post.
The Juno spacecraft successfully made a third close flyby of Jupiter on 11 Dec 2016. It was initially captured in orbit on 4 July 2016 as I noted in this blog post. The next close pass will be in early February. This brief animation illustrates a close flyby as Juno skims barely above the cloud tops of Jupiter.
On board Juno is a video camera called JunoCam. During the passes, JunoCam captures images which are sent to Earth. They are available to the public for download and processing. NASA hopes the public will use the images in creative projects. The creations can then be uploaded back to the JunoCam site for others to view.
I downloaded three images in Red, Green, and Blue of the south polar region of Jupiter. The video above shows Juno approaching over the north pole, passing very close to the equator, then receding below the south pole with each orbit. My three images were taken when Juno was directly below Jupiter’s south pole.
Using Photoshop, I opened the three RGB files, adjusted them for intensity, them combined them into this color composite. The program allowed me to adjust the saturation of many different colors across the face of the planet for enhancement. I uploaded it back to JunoCam. The colors are not realistic. But they do show the differences and circulations more readily. That was fun.