CHALLENGE

Exosky!

What would the night sky look like if you were standing on one of the many exoplanets discovered by astronomers and space missions? The list of 5500+ exoplanets at the NASA Exoplanet Archive can be combined with the latest star catalogs to translate the location and brightness of millions or even billions of stars to another perspective. From that perspective, anyone could use their imagination to draw constellations, much like our ancestors did on Earth thousands of years ago. Your challenge is to develop an app or interface for students that allows them to choose an exoplanet and then either display an interactive star chart or export a high-quality image for printing or viewing on a computer or virtual reality display, where they can draw and name constellations.

Background

During the last several decades, ground and space telescopes have been mapping the sky to create accurate catalogs of billions of stars. With distance information obtained from parallax, a three-dimensional point cloud (map) can be developed to better understand our galaxy. Beyond the science, this information also allows us to visualize how the night sky would look from one of the thousands of recently discovered planets that orbit stars other than our Sun (exoplanets). From an exoplanet’s perspective, the apparent brightness of the stars in the sky would be different from what we see from Earth, and thus the set of the brightest objects would be unique for each “exosky.” A tool that enables student users to create and visualize an exosky would help them connect our galaxy and neighboring exoplanets to their own experiences with Earth’s night sky. Star catalogs, however, are extremely large (e.g., ESA Gaia’s DR3 catalog contains information about more than one billion stars). A tool that enables visualization of an exosky will need to determine the stars that can be “seen” from an individual exoplanet and calculate their brightness from that perspective. Although these calculations involve simple geometric operations, the sheer size of the star catalogs will make these computations challenging and potentially difficult to achieve using a personal computer or web platform.

Objectives

Your challenge is to develop an app or interface that allows a student user to select an exoplanet, uses the information in a star catalog to develop a three-dimensional point cloud (map) of stars corresponding to the perspective of an observer on that exoplanet, and then creates a visualization of this point cloud. The translated point cloud could be visualized in different ways. Will your app produce a static image of the sky (like the sky charts or guides we have here on Earth), an interactive planetarium (potentially allowing for a virtual reality experience), or something else? Additional capabilities such as allowing the user to trace and name constellations would help students make each unique exosky their own, enabling a deeper experience and educational opportunity. Your tool could even provide various levels of detail (star name, color, etc.) and make different visual overlays (ecliptic, galactic grid, etc.) available for more advanced uses.

Potential Considerations

You may (but are not required to) consider the following:

• Your target audience can include elementary, middle, or high school students — or students at multiple levels!
• Note that the conversion from star catalog coordinates ("inertial") to surface coordinates ("planet-fixed") depends on the choice of a planet pole orientation.
• Your tool could:
  • Produce a simplified sky chart depicting each star as a dot (of varying size depending on its apparent brightness) to be exported—for instance as a PDF or PNG for printing (a great way for middle school students to make their own constellations).
  • Produce a photo-realistic map of the sky (e.g., see the Milky Way from an exoplanet).
  • Produce a fisheye rendering that may be explored with virtual reality hardware.
• Consider making your tool interactive with the capability to display more or less information depending on the target audience:
  • The sky chart star positions will change depending on the assumed (inertial) pole orientation, so the user may want to adjust the two angles (right ascension and declination) defining it.
  • Each star's name and information could be displayed when a user clicks or hovers a cursor on the star.
  • Each user could interactively draw constellations (by joining pairs of stars) and name them.
  • Equatorial and galactic grids and coordinates may be useful to display for higher level users.