Highlights

  • Estrella Resources has commenced a MobileMTd UAV electromagnetic survey at the Ira Miri Manganese Project in Timor-Leste.
  • Survey developed by Expert Geophysics using next-generation airborne passive EM technology.
  • Program aims to test extensions of known high-grade manganese mineralisation.
  • Previous IP surveys identified deeper anomalies that remain untested by drilling.
  • MobileMTd system enables high-resolution subsurface imaging to depths of up to 500–800 metres.
  • Survey will cover both the Ira Miri pit area and a 5km strike corridor.
  • Results intended to support drill targeting and future Mining licence applications.
  • Prior extraction program defined a 27,371-tonne manganese stockpile at 28.64% Mn average grade

Estrella Resources Limited (ASX:ESR) remained unchanged at AUD 0.036 on 19 May 2026, even as the company released a new exploration update detailing the commencement of a high-technology geophysical survey at its Ira Miri Manganese Project in Timor-Leste.

Despite the flat daily movement, the stock remains 10% lower over the past year, reflecting a broader period of mixed sentiment as the company continues to progress exploration and development activities across its portfolio.

Market attention in this session appeared focused on the company’s decision to deploy advanced airborne geophysical technology aimed at refining and extending the known manganese system.

Estrella Commences Next-Generation UAV Survey at Ira Miri

Estrella Resources has officially commenced a Mobile MagnetoTellurics (MobileMTd) UAV-based electromagnetic survey at its Ira Miri Manganese Project located in Lautém, Timor-Leste.

The program is being conducted in collaboration with Expert Geophysics, a specialist airborne geophysical services provider, and is designed to assess the potential for extensions to the existing high-grade manganese mineralisation.

The survey represents a shift toward advanced subsurface imaging techniques aimed at improving geological understanding and targeting efficiency within the project area.

According to the company, the MobileMTd system uses passive electromagnetic signals and UAV deployment to collect continuous geophysical data along flight paths, allowing for more detailed subsurface mapping compared to conventional ground-based techniques.

Purpose: Testing Depth and Strike Extensions of Mineralisation

The primary objective of the survey is to evaluate whether the known manganese mineralised system extends beyond the current pit area, both at depth and along strike.

Estrella Resources is also aiming to better understand the geometry and continuity of deeper targets previously identified through ground-based induced polarisation (IP) surveys.

These earlier IP surveys had highlighted multiple anomalies beneath and adjacent to the current pit area. However, limitations in penetration depth and resolution meant these targets remained untested through drilling.

The new UAV-based survey is designed to address these limitations by providing deeper and higher-resolution subsurface imaging across a broader area.

Technology: MobileMTd Enables Deeper Geological Imaging

The MobileMTd system is described as a next-generation airborne geophysical platform developed by Expert Geophysics.

It operates using natural electromagnetic fields, enabling passive data collection without the need for ground-based transmitters. This reduces logistical requirements while allowing for large-scale coverage of complex terrain.

Key technical features highlighted by the company include:

  • Effective sampling intervals of approximately 5 metres
  • Depth penetration potential ranging between 500 and 800 metres, depending on subsurface conditions
  • High-resolution imaging capability for structural and mineralisation mapping
  • UAV deployment allowing access to steep or rugged terrain without extensive ground infrastructure

The company has noted that this approach provides a significant improvement in both spatial resolution and depth capability compared to prior survey methods used at Ira Miri.

Survey Area and Geological Focus

The UAV survey will cover the existing Ira Miri pit area as well as an extended strike corridor of approximately 5 kilometres.

This broader coverage area is intended to capture both known manganese mineralisation zones and adjacent structural features identified through earlier geological mapping.

Estrella Resources has indicated that the survey will help refine structural interpretations and assist in identifying potential extensions of the manganese system beneath cover and along strike.

The geological focus remains on better defining mineralisation controls and understanding how the system evolves beyond currently exposed or historically tested zones.

Background: Existing High-Grade Manganese System

The survey follows the completion of Estrella’s Category B market appraisal extraction program at Ira Miri.

That program resulted in the definition of a Stage 1 stockpile of approximately 27,371 tonnes of manganese ore, with a weighted average grade of 28.64% Mn.

The company also reported in-situ grades reaching up to 60.22% Mn within the pit area, highlighting the presence of high-grade mineralisation associated with structurally complex zones.

This existing dataset provides a baseline for the new geophysical work, which is intended to expand understanding of the system beyond the currently defined extraction zone.

Integration with Previous Geophysical Work

Earlier ground-based induced polarisation (IP) surveys had already identified multiple deeper geophysical anomalies located beneath and adjacent to the current pit.

However, these anomalies remained largely untested due to depth and resolution limitations associated with conventional ground-based survey techniques.

The MobileMTd UAV survey is expected to provide a higher-resolution dataset capable of resolving these deeper structures more clearly.

Estrella Resources intends to use this new dataset to compare methodologies and assess the potential for broader application of UAV-based electromagnetic surveying across its project portfolio.

Next Steps: Data Processing and Exploration Planning

Field Acquisition for the survey is expected to take approximately three weeks, subject to weather and operational conditions.

Following completion of data collection, processing and interpretation are anticipated to take an additional six to eight weeks.

The company expects the results to contribute to:

  • Ranking and prioritisation of deeper drill targets
  • Refinement of the geological and structural model at Ira Miri
  • Assessment of broader scale mineralisation potential
  • Support for future Category A Mining Licence application

In parallel, Estrella is also advancing export preparations for its manganese stockpile, with testing and sales processes expected to continue in the near term.

What This Means for Investors

The commencement of a UAV-based geophysical survey represents an important exploration step for Estrella Resources as it seeks to better define the scale and continuity of the Ira Miri manganese system.

While no immediate production or resource upgrade has been announced, the program is aimed at improving targeting confidence and identifying deeper or lateral extensions of known mineralisation.

Investor focus is likely to remain on upcoming survey results, particularly in relation to whether deeper anomalies can be confirmed and prioritised for drilling.

The update reflects continued exploration momentum at Ira Miri, supported by prior high-grade extraction results and expanding geophysical coverage.