Current Events

Current Event: The Eta Aquariids are Coming!


By Stacy Palen

Don’t forget to remind your students about the Eta Aquariid Meteor Shower, coming in the beginning of May.  The peak occurs around May 4-5.  This is the last chance for most of us to remind Spring semester students to go out and watch a meteor shower!

This meteor shower occurs when Earth passes through the debris left behind by Halley’s Comet.  Particles lost from the comet continue to drift in the Solar System, gradually changing their position. As Earth moves through space, it passes near the trajectory of the comet and runs into collections of these particles.  The particles burn up, creating meteors as they fall through the atmosphere. This will happen repeatedly at particular times of year, as Earth returns to the same point in its orbit. 

Halley’s comet has a 76-year orbit, so it is a short-period comet. It will not be back in the inner Solar System until 2061.

To watch a meteor shower, go to a clear dark sight where the horizon is not obstructed.  Spend about half an hour in the dark, without your cell phone or other bright light in view.  This will allow your eyes to adapt to the dark. Then just watch for meteors!  They are best seen with the naked eye.

If you are careful and methodical, your observations can contribute to the study of meteors and meteor streams!  To learn more, visit the Astronomical League’s Meteor Observing Program website.

Current Events: We've Landed on Mars! Again!

By Stacy Palen.

As of this writing, InSight has just landed successfully on Mars!  This mission is a little bit different from other recent missions: InSight (short for Interior Exploration using Seismic Investigations) is a lander, not a rover. Because it’s in the news, this is a great opportunity for a brief in-class discussion!


This illustration shows a simulated view of NASA's InSight lander descending on its parachute toward the surface of Mars. Credits: NASA/JPL-Caltech

InSight is designed to investigate the interior of Mars: the crust, mantle, and core.   

A seismometer will measure surface vibrations, which will be used to determine the size of the core, the thickness and structure of the crust, and therefore the thickness of the mantle as well. These same measurements will be used to measure how frequent and how powerful the tectonics are on Mars, as well as the frequency of meteorite impacts.

Heat flow measurements will be taken using a probe that is hammered 5 meters (16 feet) down into the surface. These measurements will be used to determine the temperature of the interior. All of these measurements will lend insight (ha!) into the formation and evolution of Mars.

Radar soundings back and forth to an orbiting spacecraft will be used to measure the wobble of Mars on its axis, which in turn is affected by the structure and composition of the core.

The InSight lander is the result of many technical advances. It’s the first lander to pick up and place instrumentation from the top of the lander onto the surface of the object being studied.

The plan is for InSight to place its seismometer on the surface of Mars, then place a heat and wind shield directly on top of the seismometer. The lander needs to make these placements autonomously, something that has never been done before.

In another major technological advance, InSight arrived on the Martian surface through a complex series of steps involving parachutes and retrorockets. The successful operation of these kinds of tools is a pre-requisite for future human exploration. Just InSight's successful landing represents a major step forward in the study of Mars.


An artist’s rendition of the InSight lander operating on the surface of Mars. Image Credit: NASA/JPL-Caltech

Discussion questions for students may be wide-ranging:

  • How does this mission connect to earlier discussions about the formation and structure of planets? (Hooray for final exam review!)
  • Why do we care about the structure of Mars? What implications might a study of the geologic properties of Mars have for future Mars exploration?
  • Do you expect the meteorite impacts to be frequent (more than one per day) or rare (less than one per sol)? Why?

And here are some quick “Google It and Think” questions for small groups:

  • How long did it take for this mission to get to Mars? What factors determined this “flight” time?  What challenges would humans face due to this travel time on a trip to Mars?
  • How many spacecraft, rovers, and landers are currently functioning on Mars? Why is Mars a unique target for missions like these?
  • There are three separate stages for the entry, descent, and landing sequence. What are they?  What problems can you think of that might have occurred in each stage? What steps did the engineering team take to make these problems less likely?