Proposal: Exoplanet bath


Want to bathe in a universe of extra-solar planets and adopt one for yourself?

A ball pit that has 1781 balls, one for each known exoplanet. Each ball has a barcode/QR code on it which can be scanned to go to a webpage that gives you all the data on the corresponding exoplanet and allows you to print out a certificate for “finding” that exoplanet.


Time and location of installation

Possibly at Science Hack Day San Francisco 2014


A collaboration with Ariel Waldman. Scientific advice from Phil Marshall.


Questions/working notes

Color: What property of exoplanets should ball color correspond to? Possibly temperature, which could be a proxy for habitability. Petigura et al (2013) provide insolations, but not (I think) temperatures.

What  kind of stickers will be best for attaching to balls so they won’t come  off from people rolling around in the balls but can be removed later?  Or should they be permanent attachments?

Are QR codes too much of a barrier for most people? Should they just be labeled with names instead? Resolution: Just label with QR code plus name on a sticker.

Should the labels be written on with sharpie? (At 20 seconds per label this would take upwards of 10 hours of effort) Are some of the labels too long to fit on a ball? e.g. OGL-2008-BLG-355L b

The volume of balls is about 1 cubic meter if we used 7cm diameter balls.

Source of balls: e.g.

Some science twitter conversation:
Tom Barclay @mrtommyb
@drphilmarshall For outreach could assume earth-like and use Teq = Teff(R/2a)^0.5 [f(1−A)]^0.25, A~0.3, f=1. Tsurface=55+Teq.

Phil Marshall @drphilmarshall
@mrtommyb Nice! Teff and R are in Petigura’s table, I suppose. What temperature does Earth have with this formula? Thanks! 🙂

Tom Barclay @mrtommyb
@drphilmarshall Teff, R and a should be in Petigura’s paper or at least derivable (Rp/R*, a/R* etc.). Teq for Earth is abut 255 K.