Waiting for MU69 to Be Star-Crossed

Waiting for MU69 to Be Star-Crossed

2018-12-21

Explanation: How do we know where our next object is? By watching it pass in front of distant stars. MU69 will cast a tiny star-shadow on Earth when it passes in front of a star from our vantage point. But, exactly where on Earth that shadow is cast is dependent on exactly where MU69 is on the sky. The NASA New Horizons mission sent teams across the planet over the last few years to wait for just such crossing events to help determine exactly where MU69 is in space. This picture was taken by Jack Jewel in Senegal in 2018. It features (left to right) Souleymane Gueye, Cathy Olkin (New Horizons Co-I), and Jack Jewell. (And while the low clouds might be pretty, they’re not good for star gazing!)

Image credit: Jack Jewel

Bennu and MU69 to-Scale

Bennu and MU69 to-Scale

2018-12-20

Explanation: The end of 2018 has seen a lot of news for NASA space missions. Among them is NASA’s OSIRIS-REx reaching its target, Bennu, and NASA’s New Horizons flying by its target, ΜU69. But just how big are these bodies? Bennu is about 550 meters, or 0.33 miles, across. Μ69 is estimated to be 20–30 kilometers, or 12–19 miles, across. This significant difference can be hard to visualize, so today’s Picture of the Day puts the two to their proper scale. Make sure to click on the image to see it larger so you can see Bennu.

Image credit: NASA / Southwest Research Institute / Stuart J. Robbins (composite)

Kuiper Belts Around Other Stars

Kuiper Belts Around Other Stars

2018-12-19

Explanation: From our vantage point in space, we can only see individual Kuiper Belt Objects in our own solar system. But, around other stars, the collective light from all those objects is bright enough to see from Earth. The Hubble Space Telescope has imaged these belts of material around numerous other stars. In this Picture of the Day, we show you 15 of them.

Image credit: NASA / Mark Clampin (2010)

Resolution of MU69 Downloads After New Year’s Day, 2019

Resolution of MU69 Downloads Before New Year’s Day, 2019

2018-12-18

Explanation: It takes a long time to bring down a single image from where New Horizons will be on New Year’s Day, 2019. So long that just a few can be downloaded in a day. The flyby is also extremely fast so MU69 will only be resolved (more than a pixel or so across) in the few hours around the flyby. From this tight timetable, this Picture of the Day simulates what we expect images (that we will have on the ground) to look like in the two days after the closest approach. The object used in this simulation is Saturn’s moon Phoebe, and we have used a nominal, estimated size of 30 km across for MU69. See yesterday’s Picture of the Day for what we expect to see in the two days before!

Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute

Resolution of MU69 Downloads Before New Year’s Day, 2019

Resolution of MU69 Downloads Before New Year’s Day, 2019

2018-12-17

Explanation: It takes a long time to bring down a single image from where New Horizons will be on New Year’s Day, 2019. So long that just a few can be downloaded in a day. The flyby is also extremely fast so MU69 will only be resolved (more than a pixel or so across) in the few hours around the flyby. From this tight timetable, this Picture of the Day simulates what we expect images (that we will have on the ground) to look like in the two days before the closest approach. The object used in this simulation is Saturn’s moon Phoebe, and we have used a nominal, estimated size of 30 km across for MU69. See tomorrow’s Picture of the Day for what we expect to see in the two days after!

Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute

Comparing Best Images at Pluto to MU69

Comparing Best Images at Pluto to ΜU69

2018-12-16

Explanation: At the time of this writing, the actual flyby trajectory has not yet been set, but our prime trajectory will take us within 3000 km of ΜU69. That will let us take images as good as 30 meters per pixel, more than twice as good as what we took at Pluto, and more than five times better than our best images of Charon. This is a simulated image of New York City showing the comparison.

Image credit: Google Earth / NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute

MU69 Is Getting Closer: Latest Shots

ΜU69 Is Getting Closer: Latest Shots

2018-12-15

Explanation: As NASA’s New Horizons spacecraft gets closer and closer to MU69, or “Ultima Thule,” it is taking dozens of images practically every day. Scientists on the ground are busy analyzing those to search for any potential hazards so the spacecraft’s trajectory can be altered in time if the hazards are considered significant enough. This image on the left shows one of those hazard images from December 2, 2018, from a distance of about 24 million miles (39 million km). The image on the right is MU69 itself with all of the stars removed so that the target pops out. Remnants of imperfect star subtraction are seen around the body, but the team is getting to know the star field pretty well by this point!

Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute

Expectations, Part 2: Imaging Simulation ΜU69

Expectations, Part 2: Imaging Simulation ΜU69

2018-12-13

Explanation: When New Horizons flies by its next target on January 01, 2019, it will be taking a lot of pictures with its various cameras and also collecting other data such as compositional information and searching for small moons an any atmosphere around ΜU69. But, not everything is completely ideal. The craft will be flying by very fast – about 14 km/sec (31,000 miles per hour). It will also be very far from the Sun, meaning that the object is dimly lit by the sun. Scientists have planned for this in figuring out how long the cameras exposures need to be in order to record an image, but also how short the exposures need to be in order to not be blurred because of the motion. We expect our best images of ΜU69 to look something like this image of Mars’ moon Phobos, which has been degraded to simulate image noise from the 0.025-second camera exposures and a little bit of motion blur from the fast flyby.

Image credit: Moore et al. (2018) “Great Expectations: Plans and Predictions for New Horizons Encounter with Kuiper Belt Object 2014 Μ69 (“e;Ultima Thule”e;)

Expectations, Part 1: Imaging of ΜU69

Expectations, Part 1: Imaging of ΜU69

2018-12-12

Explanation: New Horizons has three scientific instruments that it can use to take pictures. LORRI is the primary camera and it is black-and-white, MVIC takes images in black-and-white or four colors, and LEISA is a near-infrared imaging spectrometer used to collect compositional information. Each has a different field of view (FOV). This image shows the fields of view of the different imagers during the planned closest approach of about 3000 km (2000 miles) from ΜU69 on January 01, 2019.

Image credit: Moore et al. (2018) “Great Expectations: Plans and Predictions for New Horizons Encounter with Kuiper Belt Object 2014 Μ69 (“e;Ultima Thule”e;)