Mars Opposition FAQ


The word opposition comes from the Latin word opponere, meaning "set against". In the case of Mars, opposition refers to the red planet being on the opposite side of the Earth from the sun.

Due to orbital placement, Mars and the sun are on opposite sides of Earth and we experience opposition roughly once every two years. What makes events like this one particularly interesting is that every 15-17 years opposition occurs when Mars is at Perihelion, its closet approach to the sun and therefore closest proximity to earth. This means with the right observing equipment we can experience Mars better than at other times of the year and it is significantly brighter in our night sky; 1.5x brighter than Jupiter.

For a video explaining this, visit SciNews.

What Else will there be to observe?

During our Mars Opposition Excursion there is so much more to see than the red planet. Five other planets, and one dwarf planet will be up in the night sky;

  • Venus
  • Jupiter
  • Saturn
  • Neptune
  • Uranus
  • Pluto

It will also be an awe inspiring weekend for low earth orbit observing. We will have:

  • one iridium flare
  • two Hubble Space Telescope passes
  • a pass of the International Space Station.

47 constellations will be viewable throughout the night and 103 Messier objects can be observed.


Of the 90+ state parks in Texas, Kickapoo Cavern State Park is one of only ten boasting Bortle 2 skies. Of those ten parks, Kickapoo Cavern is the only one in the Hill Country Region where overnight camping is allowed. All other Bortle 2 state parks are located in Big Bend Country and Panhandle Plains regions, over twice the driving distance from Central Texas. The park is at an elevation of roughly 1800 feet with very little terrain much higher in the vicinity. This allows for more sky exposure.


John E. Bortle is an amateur astronomer best known for creating a scale, named for him, that quantifies night sky darkness. The scale runs numerically from 1 to 9. Skies are classified by their naked-eye limiting magnitude (NELM) and their sky quality meter (SQM) reading. In class 2 skies you can see zodiacal light (caused by sunlight scattered via interplanetary dust), airglow (faint emissions of light caused by the atmosphere) near the horizon, many objects naked-eye that are typically only telescopic and highly structured regions of the Milky Way.


The group site is composed of five camp areas supporting six individuals per area. Each site boasts ample ground for observational equipment and camping purposes as well as a picnic table. There are four potable water faucets in the immediate vicinity along with three waist height fire grills and two fire rings. Two of the five sites are wheelchair accessible and parking is directly adjacent to the camping areas. A restroom facility will be provided onsite. Park restrooms and shower facilities are located .25 miles to the northeast of the group camp site. 

What do the event shirts look like?

what daytime activities are available?

Onsite at the group camp area there will be a shaded common space for conversation and relaxation. This is also where beverages and snacks will be available. Along with general visiting, attendees can take part in safe solar observing and lawn games (bocce ball, croquet and horseshoes).

Kickapoo cavern offers many daytime activities including hiking, mountain biking, birding, and cave tours. For those interested, a 2-hour cave tour is offered on Saturday at 1:00 p.m. Reservations are made through the park directly and cost $10 per person with a maximum of 20 people. To participate in the cave tour, you must wear sturdy closed toe shoes and loose clothing to allow for movement, have water, and two light sources (hand held flashlights are recommended). The cave system is undeveloped and does involve moderate climbing over boulders and along underground walkways. The tour is not recommended for anyone with leg, knee or foot conditions.

The park has seven defined trails training in distance from .4mi to 6.4mi and from easy to strenuous in difficulty. Kickapoo Cavern SP also sports five points of interest including; a plaque at Seargeant Memorial trail-head memorializing the trail-head's namesake, a vista at Armadillo Lookout, popular birding areas at Vireo Vista/Barbado Ridge trail-heads, Bee Cave sinkhole and Stuart Bat Cave.

Located 21 miles directly south of the park is the town of Brackettville. It is home to several local eateries including Julie's Place (comfort food), The Pizza Outpost, Darla's Kitchen (taco joint), Brackett Burger & Shake, and Ziggy's Roadside BBQ. Forty-five minutes to the northeast is the town of Rocksprings; known for Jailhouse Bar & Grill, Devil's Sinkhole State Natural Area and being the Angora Goat capital of the world.

How far is it to Kickapoo Cavern State Park?

From Austin - 226 miles / 4 hours
From Fredericksburg - 145 miles / 2.5 hours
From Houston - 375 miles / 6.25 hours
From San Antonio - 180 miles / 3 hours

*please note this are general figures, your time and mileage may vairy

if i don't want to camp, are their other lodging options?

In Brackettville there is the Fort Clark Springs Motel with rates ranging from $64-$75/night. In Rocksprings you have Sorrells Inn at around $66/night and the Historic Rocksprings Hotel, $95-$105/night.

what kind of weather can be expected?

At the beginning of August the average daytime high is 96* with an average low of 72*. The precipitation is never more than 2" and winds are low to moderate. Please plan for such a climate and cover up when out during the day. Ensure that whatever equipment you are bringing is adaquatly weighted down.

when are the moon and sun rise and set times?

Friday, August 3
     Moon set - 11:25 p.m. (3rd quarter moon)
     Sunset - 8:24 p.m.
Saturday, August 4
     Moon rise - 12:30 a.m.
     Sunrise - 7:01 a.m.
     Moon set - 12:19 p.m.
     Sunset - 8:28 p.m.
Sunday, August 5
     Moon rise - 1:04 a.m.
     Sunrise - 7:01 a.m.