The coronograph is a fundamental optical instrument in various areas of astrophysics, whose function is to block or reduce the extremely intense light emitted by a star. This capability allows scientists to observe less luminous objects and structures near the star that would otherwise be obscured by its intense brightness.
To achieve this blockage, the device employs discs and masks that hide the strongest light from the star, simulating an artificial eclipse. By reducing the central brightness, it becomes more feasible to investigate what exists around it, such as the solar corona, the Sun's outer atmosphere, or even identify planets orbiting other stars. An interesting parallel is drawn with the total solar eclipse, where the Moon acts as a 'natural coronograph' by covering the bright solar disk.
This technology is applied both in the study of the Sun and in the search for exoplanets. A notable example is the Solar and Heliospheric Observatory (SOHO), a collaboration between NASA and the European Space Agency (ESA), which uses the Large Angle and Spectrometric Coronagraph (LASCO). This instrument blocks the direct light from the solar disk, enabling the observation of the corona and the monitoring of events such as coronal mass ejections.
In the field of stellar astrophysics, the James Webb Space Telescope (JWST), belonging to NASA, employs coronagraphs in its NIRCam and MIRI components. This allows for the capture of direct images of gas giant planets and the dust disks surrounding other stars.
A significant technological advance is anticipated with the Nancy Grace Roman Space Telescope, developed by NASA and scheduled for launch on August 30. This telescope will be equipped with the Coronagraph Instrument (CGI), which will use high-precision deformable mirrors and sophisticated algorithms to dynamically nullify scattered light. This capability will allow for unprecedented contrast, suppressing stellar brightness by a ratio of one to one billion.
Thanks to this functionality, the Nancy Grace Roman telescope will be able to photograph and analyze the atmospheric composition of exoplanets comparable to Jupiter and Saturn. This mission will serve as a crucial test for future investigations of rocky and potentially habitable worlds.
During the Space View program, presented by astronomer Marcelo Zurita, astrobiologist Raíssa Estrela, a researcher at NASA's Jet Propulsion Laboratory (JPL), detailed the functioning of the CGI. She explained that the coronograph is a device that blocks the light of the host star because the stellar brightness completely obscures the image, preventing the visualization of light reflected by the planets. Blocking this light is essential to observe these planets in orbit and image the planetary system.
Raíssa emphasized that this is the main differential of the equipment, as it will move from indirect measurements, as currently done with James Webb, to allowing the direct imaging of planets.
Despite the monumental leap that Roman represents for astronomy, it was not designed to directly analyze the atmosphere of Earth-sized rocky planets in search of biosignatures. However, its mission establishes the indispensable foundation for the discovery of a 'Earth 2.0' to become achievable.
The operational use of the coronograph in space and the data collected by Roman will serve as a testing ground for the development of astronomical missions in the coming decades. This applies to the future Habitable Worlds Observatory, a project planned by NASA for the 2030s and 2040s, focused exclusively on searching for chemical indicators of life on planets similar to ours.
Raíssa clarified that current technology does not yet allow for the detection of molecules in an atmosphere like Earth's. Therefore, the current work aims to prepare the ground so that in a few years, there will be a space telescope capable of performing such science.
The JPL researcher stressed that studies with Roman will pave the way for future generations of astrobiologists. Although Roman primarily focuses on gas giants, it will bring the necessary technology for the direct imaging of exoplanets, which will be used by the Habitable Worlds Observatory for smaller planets, thus marking the first step on this journey toward characterizing Earth-like planets.
On August 9, 2026, the Moon was in the waning phase, with 15% visibility. The National Institute of Meteorology (Inmet) provided the complete calendar of lunar phases for August 2026.
The lunar phases in August 2026 began on the 5th with the Waning Moon, recorded at 11:22 PM Brasília time. Subsequently, the New Moon occurred on the 12th at 2:37 PM. The Waxing Moon appeared on the 19th at 11:46 PM, culminating with the Full Moon on the 28th at 1:19 AM.
A lunar cycle, also known as a lunation, refers to the time interval between two new moons and has an average duration of 29.5 days. During this period, the Moon passes through four main phases: new, waxing, full, and waning, with each phase lasting approximately seven days.
In addition to these main phases, there are so-called 'interphases,' which include the first quarter and the gibbous crescent (located between the new and full phases), and the gibbous waning and the last quarter (located between the full and waning phases).
During the New Moon phase, the satellite is positioned between the Earth and the Sun. This results in only the side illuminated by the Sun facing the Sun, while the dark side faces us, making the Moon invisible in the night sky. This phase signals the beginning of a new lunar cycle and is associated with renewal and new opportunities.
After the New Moon, the Waxing phase begins. Slowly, a thin band of light starts to be observed in the sky, progressively increasing each night. Initially, only a faint arc of light is seen, but as the days advance, the illuminated area grows until half of the Moon is visible, a stage called First Quarter. This phase symbolizes development, growth, and the building of new paths.
During the Full Moon phase, the Earth is located between the Sun and the Moon. This configuration allows the entire lunar face facing us to receive complete illumination, making it fully visible and bright in the firmament. This is the period of maximum luminous intensity, occurring when the Moon rises on the horizon simultaneously with sunset. The Full Moon is associated with fullness, the peak of processes, and energy at its highest level.
After the Full Moon, the lunar luminosity begins to gradually decline. Each night, a decrease in the illuminated surface is observed. When half of the Moon is visible, the Last Quarter occurs, which is the opposite of the First Quarter. The Moon continues to lose brightness until it returns to the New Moon, thus restarting the cycle. The Waning phase represents reflection, conclusion, and preparation for subsequent beginnings.
On August 6, 2026, the Moon will be in the waning phase, showing 45% visibility. The National Institute of Meteorology (Inmet) has made available the complete calendar of lunar phases for this month.
The phases for August 2026 began on the 5th with the Waning Moon at 11:22 PM Brasília time. Subsequently, the New Moon will occur on the 12th at 2:37 PM. The Waxing Moon will be visible starting on the 19th at 11:46 PM, and the Full Moon will happen on the 28th at 1:19 AM.
A lunar cycle, also known as lunation, is a time interval that varies slightly, averaging 29.5 days. During this period, the Moon passes through the four main phases—new, waxing, full, and waning—with each phase lasting approximately seven days.
In addition to these main phases, there are so-called 'interphases': the first quarter and the gibbous waxing (located between the new and full phases), and the gibbous waning and the last quarter (located between the full and waning phases).
During the New Moon phase, the satellite is positioned between the Earth and the Sun. This results in only the side illuminated by the Sun facing away from us, while the dark side faces us, making the Moon invisible in the night sky. This phase signals the beginning of a new lunar cycle and is associated with renewal and new opportunities.
After the New Moon, the Waxing phase begins. Slowly, a thin illuminated band starts to appear in the sky, progressively increasing each night. Initially, only a faint arc of light is observed, but as the days advance, the illuminated area grows until it reaches half of the Moon, a moment called First Quarter. This phase represents development, growth, and the building of new paths.
During the Full Moon phase, the Earth is located between the Sun and the Moon. This configuration allows the entire lunar face facing us to receive complete illumination, making it fully visible and radiant in the firmament. This is the period of maximum luminous intensity, occurring when the Moon rises on the horizon simultaneously with sunset. The Full Moon is associated with fullness, the peak of processes, and energy at its highest level.
After the Full Moon, the lunar luminosity begins to gradually decline. Each night, the illuminated portion of the surface decreases. When half of it is visible, the Last Quarter occurs, which is the opposite of the First Quarter. The Moon continues to lose brightness until it returns to the New Moon, thus restarting the cycle. The Waning phase symbolizes reflection, conclusion, and preparation for subsequent beginnings.
On August 4, 2026, the Moon is at the last day of the full phase, showing 60% visibility. The National Institute of Meteorology (Inmet) has made available the complete calendar of lunar phases for the month of August.
The next lunar transitions in August 2026 are scheduled to begin with the Waning Moon on the 5th, at 11:22 PM (Brasília time). Subsequently, the New Moon will occur on the 12th, at 2:37 PM. The Waxing Moon will appear on the 19th, at 11:46 PM, and the cycle will conclude with the Full Moon on the 28th, at 1:19 AM.
The lunar cycle, also known as lunation, refers to the time interval between two new moons and has an average duration of 29.5 days. During this period, the Moon passes through four main phases: new, waxing, full, and waning, with each phase lasting approximately seven days. In addition to these main phases, there are so-called 'interphases,' such as the first quarter and the gibbous crescent (between new and full), and the gibbous waning and the last quarter (between full and waning).
During the New Moon phase, the satellite is positioned between the Earth and the Sun. Consequently, the illuminated side faces the Sun, while the dark side is turned towards us, making the Moon invisible in the night sky. This phase signals the beginning of a new lunar cycle, associated with renewal and new opportunities.
After the New Moon, the Waxing phase begins. A thin band of light starts to be observed in the sky and progressively increases each night. Initially, only a faint arc of light is seen, but this illuminated area grows until half of the Moon is visible, a stage called First Quarter. This phase represents development, growth, and the building of new paths.
In the Full Moon phase, the Earth is located between the Sun and the Moon. This ensures that the entire lunar face facing the Earth receives complete illumination, making it fully bright and visible in the sky. This is the period of maximum luminous intensity, occurring when the Moon rises on the horizon simultaneously with sunset. The Full Moon is linked to fullness, the peak of processes, and energy at its highest point.
Concluding the cycle, after the Full Moon, the lunar brightness begins to gradually decrease. Each night, a smaller portion of its illuminated surface becomes visible. When half of the Moon is visible, the Last Quarter occurs, which is the opposite of the First Quarter. The Moon continues to lose brightness until it returns to the New Moon, thus restarting the cycle. The Waning phase symbolizes reflection, closure, and preparation for future beginnings.
Today, the Moon is in the Full phase.
