craters {sphunif} | R Documentation |
Craters named by the IUA
Description
Named craters of the Solar System by the Gazetteer of Planetary Nomenclature of the International Astronomical Union (IUA).
Usage
craters
Format
A data frame with 5235 rows and 7 variables:
- ID
database ID.
- name
name of the crater.
- target
name of the celestial body. A factor with 43 levels, such as
"Moon"
,"Venus"
, or"Europa"
.- target_type
type of celestial body. A factor with 3 levels:
"Planet"
,"Moon"
,"Dwarf planet"
, or"Asteroid"
.- diameter
diameter of the crater (in km).
- theta
longitude angle
\theta \in [0, 2\pi)
of the crater center.- phi
latitude angle
\phi \in [-\pi/2, \pi/2]
of the crater center.
Details
"Craters" are understood in the Gazetteer of Planetary Nomenclature as roughly circular depressions resulting from impact or volcanic activity (the geological origin is unspecified).
Be aware that the dataset only contains named craters by the IUA.
Therefore, there is likely a high uniform bias on the distribution
of craters. Presumably the naming process attempts to cover the planet in
a somehow uniform fashion (distant craters are more likely to be named than
neighboring craters). Also, there are substantially more craters in the
listed bodies than those named by the IUA. See venus
and
rhea
for more detailed and specific crater datasets.
The (\theta, \phi)
angles are such their associated planetocentric
coordinates are:
(\cos(\phi) \cos(\theta), \cos(\phi) \sin(\theta), \sin(\phi))',
with (0, 0, 1)'
denoting the north pole.
The script performing the data preprocessing is available at
craters.R
. The data was retrieved on 2020-05-31.
Source
https://planetarynames.wr.usgs.gov/AdvancedSearch
Examples
# Load data
data("craters")
# Add Cartesian coordinates
craters$X <- cbind(cos(craters$theta) * cos(craters$phi),
sin(craters$theta) * cos(craters$phi),
sin(craters$phi))
# Tests to be performed
type_tests <- c("PCvM", "PAD", "PRt")
# Tests for Venus and Rhea
unif_test(data = craters$X[craters$target == "Venus", ], type = type_tests,
p_value = "asymp")
unif_test(data = craters$X[craters$target == "Rhea", ], type = type_tests,
p_value = "asymp")