This page contains a selection of interesting multimedia used as part of presentations or publications. Most of the content is original from the PHL, but other sources are credited.
This plot shows the extension of the recently redefined Habitable Zone around F, G, K, and M stars. The Warm 'Habitable' Zone is divided into a narrower 'Conservative Habitable Zone' (light green) and a wider 'Optimistic Habitable Zone' (dark green). Earth is at the inner edge of the 'Conservative Habitable Zone.' CREDIT: PHL @ UPR Arecibo.
is the NASA's first mission capable of finding Earth-size planets. This big infographic shows some important figures of the mission up to March 2013. Click for a larger image. Credit: Aliona Voitenko.
Esta imagen de Puerto Rico combina fotos de NASA Blue Marble
y Black Marble
para crear una imagen amplificada de la iluminación nocturna en Puerto Rico. Los fuegos artificiales serían unos puntos a esta escala, pero fueron añadidos y exagerados en tamaño porque así lo celebramos en nuestra isla. ¡Feliz Año 2013!
English Caption: This image of Puerto Rico combines photos from NASA Blue Marble and Black Marble to create an amplified image of the night illumination of Puerto Rico. The fireworks would barely occupy dots at this scale, but were added and exaggerated in size because that is the way we celebrate it in our island. Happy New year 2013!
This is an excellent infographics of the nearest 53 star systems. Here
is a more detailed list of 270 stellar systems within 10 parsecs. CREDIT: Karl Tate, Space.com
The 'X-mas Planets' is a collage of computer generated images of habitable worlds by the Planetary Habitability Laboratory (PHL) over an image of a section of the De Mairan’s Nebula (Messier 43)
taken by the Hubble Space Telescope. Earth is at the top right. This image was done to celebrate the first year of the PHL's Habitable Exoplanets Catalog
. Credit: PHL @ UPR Arecibo (phl.upr.edu), ESA/Hubble, NASA.
Dwarf planet Pluto is so small and far away that it only shows as a featureless dim dot in any ground or space telescope. Only NASA's New Horizon
space mission will get close enough to Pluto on July 2015 to observe its surface details. Now consider the stars, many are even larger than the Sun but they are much farther away. Are the apparent size of the stars larger than Pluto? They seem bigger because we can see them with the naked-eye, but in fact the apparent size of most stars are much smaller than Pluto (see figure below). It is their brightness than make them look much larger and fuzzier to our eyes and our telescopes.
If we barely see surface features on Pluto
, neither on any exoplanet, which are much smaller and dimmer than their parent stars. Only those few exoplanets bright enough
, because they are young and hot, can be directly seem in telescopes as faint points. Most are to dim and out shined that and are only detected because they affect the star light in some subtle ways.
Caption: Best image of the Pluto-Charon system
ever taken by a ground observatory. The image was taken by the Gemini North
telescope on July 2012 with an average resolution of 20 milliarcseconds (mas). We added for comparison the apparent size of Pluto and Charon (dotted circles) with those of four known stars (not including the star glare which make them look much bigger). The size of Epsilon Eridani is comparable to detecting a 5 meter diameter object on the Moon from Earth, a nearly impossible activity. Exoplanets are much smaller. CREDIT:
PHL @ UPR Arecibo, Gemini Observatory/NSF/NASA/AURA
This excellent image compilation by Mike Malaska
shows the planetary surfaces of Asteroid Itokawa, the Moon, Venus, Mars, Titan, and Earth. So our technology has been in the surface of five planetary bodies besides Earth. Well, not counting Eros
(not originally a lander), Comet Tempel 1
(a 'crasher'), and Jupiter
(not a surface to land). Why Earth is shown as an ocean? With a 71% global coverage this is the most common surface type of our planet.
Image Credits: Asteroid Itokawa [Hayabusa]: ISAS / JAXA / Gordan Ugarkovic , Moon [Apollo 17]: NASA, Venus [Venera 14]: IKI / Don Mitchell / Ted Stryk / Mike Malaska, Mars [Mars Exploration Rover Spirit]: NASA / JPL / Cornell / Mike Malaska, Titan [Cassini Huygens]: ESA / NASA / JPL / University of Arizona, Earth: Mike Malaska, Composition by Mike Malaska.
This figure shows an actual image of a sunset on Earth compared to artistic representations for the best candidates of potential habitable worlds so far. The image corrects for the size, colors, and brightness of the star and sky as seen from an Earth-like world located in the orbits of these worlds. The size of and colors of the star of Kepler-22 b look similar to Earth because it orbits a Sun-like star. The sunsets of Gliese 667Cc and 581d look much redder because they orbit a red dwarf star, with the sky of Gliese 581d much darker due to its greater distance. The star of HD 85512b is the brightest of all cases although the star of Gliese 667Cc is the biggest. CREDIT: PHL @ UPR Arecibo
Data used in the creation of the previous image:
||Apparent Magnitude from Planet
||Apparent Size from Planet (°)
| Gliese 667C
| HD 85512
| Gliese 581
For more information about these worlds check the Habitable Exoplanet Catalog (HEC)
. This data is also available to construct similar views for any of the confirmed and Kepler exoplanets candidates in the full database
of HEC. Individual frames are available under request for editorial and educational purposes only. The image of the beach was taken June 14, 2012 @ 6:45 AM AST in Puerto Rico while relaxing.
Water is not a luxury of Earth, in fact, it is the most abundant compound in the universe because it is composed of the first and third most abundant elements, hydrogen and oxygen, respectively. However, water in liquid form is a special feature of Earth. It is usually present as vapor or ice in the Solar System. After the formation of the Solar System most of the water ended on the farthest planetary bodies locked as ice in their surface or interiors. Earth being closer to the Sun has little water, relatively speaking, mostly in its surface. If Earth is a wet rock the satellites of Jupiter and Saturn are frozen mud balls. Water ice in these satellites is more evenly distributed through their interior than in rocky bodies. We also know that liquid water is not only a luxury of Earth and is also present as deep oceans in Europa
, satellites of Jupiter and Saturn, respectively (Figure 1). The amount of liquid water in Enceladus, a satellite of Saturn, and Mars are probably large too.
Figure 1. Comparison of the liquid water volume of Earth, Europa, and Titan to scale. It is estimated that Europa has over two times and Titan nearly eleven times more liquid water as subsurface oceans than Earth. Only liquid water is considered in these estimates but water ice is also significantly present in Europa and Titan. The image assumes a mean ocean depth of 4 km, 100 km, and 200 km for Earth, Europa, and Titan, respectively. CREDIT: PHL @ UPR Arecibo, NASA.
Here we tried to reproduce the global surface color of Venus as seen by the human eye based on radar imagery from the Magellan
spacecraft and surface images by the Venera
missions. There are no color global images of the surface of Venus due to its thick atmospheric coverage and colorized radar images
are used instead. We combined radar topography and emissivity to generate the surface texture assuming a generalized basalt composition with gray to light brown tones, depending on the iron and sulfur content. In the images we also included the effect of the 'orange sky' of Venus thus given its surface a more dark brown appearance (Figure 1). Under white light the surface should look grayish and more similar to the Moon. We also created a fictional version with a nearly 70% ocean coverage, as Earth, to emphatize the extent of the 'continental' areas (Figure 2). SER
was used to create the images at five particular angles used by terrestrial geostationary satellites
. High resolution versions (48 megapixels) of these images are available upon request
. CREDIT: PHL @ UPR Arecibo, NASA.
Figure 1. Approximate representation of the real colors, as seen by human eyes, of the surface of Venus without clouds but considering atmospherics effects (i.e. Rayleigh Scattering).
Figure 2. Fictional representation of Venus today with a nearly 70% ocean coverage. Its two main 'continental' landmasses, Ishtar Terra in the North and Aphrodite Terra in the equator, are recognizable.